Digital broadcasting receiver and method for controlling the same

ABSTRACT

A method of processing broadcast data includes: performing RS encoding and CRC encoding on mobile service data to generate an RS frame belonging to an ensemble including a signaling information table including access information of the mobile service data and identification information for identifying a stream where keys to decrypt the mobile service data are obtained; mapping a portion of data in the RS frame to a group including known data sequences, FIC data, and TPC data, wherein the FIC data includes information for rapid mobile service acquisition, and the TPC data includes FIC version information for indicating an update of the FIC data; and transmitting a broadcast signal including the group. The group further includes data blocks. First, fourth, fifth and sixth known data sequences are inserted into third, fifth, sixth and seventh data blocks, respectively. Second and third known data sequences are inserted into a fourth data block.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/235,578, filed on Sep. 22, 2008, which claims the benefit of andright of priority to U.S. Provisional Application No. 60/974,084, filedon Sep. 21, 2007, U.S. Provisional Application No. 60/977,379, filed onOct. 4, 2007, U.S. Provisional Application No. 60/981,520, filed on Oct.22, 2007, U.S. Provisional Application No. 61/044,504, filed on Apr. 13,2008, U.S. Provisional Application No. 61/076,686, filed on Jun. 29,2008, and Korean Application No. 10-2008-0092445, filed on Sep. 19,2008, the contents of all of which are hereby incorporated by referenceherein in their entireties.

FIELD OF THE INVENTION

The present invention relates to a digital broadcasting receiver and amethod for controlling the same, and more particularly, to a digitalbroadcasting system and a data processing method.

DISCUSSION OF THE RELATED ART

The Vestigial Sideband (VSB) transmission mode, which is adopted as thestandard for digital broadcasting in North America and the Republic ofKorea, is a system using a single carrier method. Therefore, thereceiving performance of the digital broadcast receiving system may bedeteriorated in a poor channel environment. Particularly, sinceresistance to changes in channels and noise is more highly required whenusing portable and/or mobile broadcast receivers, the receivingperformance may be even more deteriorated when transmitting mobileservice data by the VSB transmission mode.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a digital broadcastingreceiver and a method for controlling the same that substantiallyobviate one or more problems due to limitations and disadvantages of therelated art.

Another object of the present invention is to provide a method forprocessing services having various formats in a mobile digitalbroadcasting environment.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein,there is provided a method for processing data in a reception system,the method includes receiving a broadcasting signal including mobileservice data and main service data, the mobile service data includingfirst service data and second service data having a format differentfrom that of the first service data, the second service data configuringa Reed Solomon (RS) frame, and the RS frame including a table whichdescribes the second service data and signaling information of thesecond service data, parsing the table from the RS frame and extractingthe signaling information of the second service data, and parsing thesecond service data from the RS frame on the basis of the extractedsignaling information.

At this time, at least one data group configuring the RS frame mayinclude a plurality of known data sequences, a signaling informationzone may be included between a first known data sequence and a secondknown data sequence of the known data sequences, and the signalinginformation zone may include transmission parameter channel (TPC)signaling and fast information channel (FIC) signaling.

And, the RS frame may be configured by an RS frame header and an RSframe payload, and the RS frame payload may include a transport packetconfigured by packetizing at least one piece of data, for a secondservice.

Also, the RS frame header may include at least one of first informationfor identifying the type of data in the transport packet transmitted viathe payload, second information indicating whether or not an error isincluded in the transport packet transmitted via the payload, thirdinformation indicating whether or not stuffing bytes are included in theRS frame, and fourth information indicating a start point of new data inthe transport packet transmitted via the payload.

And, the first information may identify the type of the data in thetransmitted transport packet, and the type may be identified by data fora first service and data for the second service.

Also, the transport packet transmitted via the RS payload may include aflow packet including the data for the second service.

And, the flow packet may be configured by a flow packet header and aflow packet payload, and the flow packet payload may include a layerpacket packetized in at least one layer for the second service andlength information indicating the length of the layer packet.

And, the flow packet header may include at least one of an identifierfor identifying the layer packet included in the flow packet,information indicating whether the flow packet is transmitted over atleast one RS frame, information indicating whether cyclic redundancycheck (CRC) is applied to the flow packet, and information indicatingthe number of layer packets included in the flow packet.

In another aspect of the present invention, there is provided areception system includes a baseband processor receiving a broadcastingsignal including mobile service data and main service data, the mobileservice data including first service data and second service data havinga format different from that of the first service data, the secondservice data configuring a Reed Solomon (RS) frame, and the RS frameincluding a table which describes the second service data and signalinginformation of the second service data, a table handler parsing thetable from the RS frame and extracting the signaling information of thesecond service data, and service handlers parsing the second servicedata from the RS frame on the basis of the extracted signalinginformation of the second service data.

At this time, at least one data group configuring the RS frame mayinclude a plurality of known data sequences, a signaling informationzone may be included between a first known data sequence and a secondknown data sequence of the known data sequences, and the signalinginformation zone may include transmission parameter channel (TPC)signaling and fast information channel (FIC) signaling.

At this time, the baseband processor may further include a known datadetector detecting the known data sequences included in the data group,and the detected known data sequences are used for demodulation andchannel equalization of the mobile service data.

And, the table handler may extract the table including the signalinginformation of the second service data from the RS frame configured byan RS frame header and an RS frame payload, and the RS frame payload mayinclude a transport packet configured by packetizing at least one pieceof data, for a second service.

Also, the table handler may extract and use the RS frame headerincluding at least one of first information for identifying the type ofdata in the transport packet transmitted via the payload, secondinformation indicating whether or not an error is included in thetransport packet transmitted via the payload, third informationindicating whether or not stuffing bytes are included in the RS frame,and fourth information indicating a start point of new data in thetransport packet transmitted via the payload, and one of the servicehandlers may be selected by identifying whether the type of the data inthe transmitted transported packet include the first service data or thesecond service data from the extracted first information.

And, the selected service handler may process the transport packettransmitted via the RS frame payload, the transport packet may include aflow packet including data for the second service, and the flow packetmay include a flow packet header and a flow packet payload including alayer packet packetized in at least one layer for the second service andlength information indicating the length of the layer packet.

Also, the service handlers may process the flow packet header includingat least one of an identifier for identifying the layer packet includedin the flow packet, information indicating whether the flow packet istransmitted over at least one RS frame, information indicating whethercyclic redundancy check (CRC) is applied to the flow packet, andinformation indicating the number of layer packets included in the flowpacket.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 illustrates a block diagram showing a general structure of adigital broadcasting receiving system according to an embodiment of thepresent invention;

FIG. 2 illustrates an exemplary structure of a data group according tothe present invention;

FIG. 3 illustrates an RS frame according to an embodiment of the presentinvention;

FIG. 4 illustrates an example of an MH frame structure for transmittingand receiving mobile service data according to the present invention;

FIG. 5 illustrates an example of a general VSB frame structure;

FIG. 6 illustrates an example of mapping positions of the first 4 slotsof a sub-frame in a spatial area with respect to a VSB frame;

FIG. 7 illustrates an example of mapping positions of the first 4 slotsof a sub-frame in a chronological (or time) area with respect to a VSBframe;

FIG. 8 illustrates an exemplary order of data groups being assigned toone of 5 sub-frames configuring an MH frame according to the presentinvention;

FIG. 9 illustrates an example of a single parade being assigned to an MHframe according to the present invention;

FIG. 10 illustrates an example of 3 parades being assigned to an MHframe according to the present invention;

FIG. 11 illustrates an example of the process of assigning 3 paradesshown in FIG. 10 being expanded to 5 sub-frames within an MH frame;

FIG. 12 illustrates a data transmission structure according to anembodiment of the present invention, wherein signaling data are includedin a data group so as to be transmitted;

FIG. 13 illustrates a hierarchical signaling structure according to anembodiment of the present invention;

FIG. 14 illustrates an exemplary FIC body format according to anembodiment of the present invention;

FIG. 15 illustrates an exemplary bit stream syntax structure withrespect to an FIC segment according to an embodiment of the presentinvention;

FIG. 16 illustrates an exemplary bit stream syntax structure withrespect to a payload of an FIC segment according to the presentinvention, when an FIC type field value is equal to ‘0’;

FIG. 17 illustrates an exemplary bit stream syntax structure of aservice map table according to the present invention;

FIG. 18 illustrates an exemplary bit stream syntax structure of an MHaudio descriptor according to the present invention;

FIG. 19 illustrates an exemplary bit stream syntax structure of an MHRTP payload type descriptor according to the present invention;

FIG. 20 illustrates an exemplary bit stream syntax structure of an MHcurrent event descriptor according to the present invention;

FIG. 21 illustrates an exemplary bit stream syntax structure of an MHnext event descriptor according to the present invention;

FIG. 22 illustrates an exemplary bit stream syntax structure of an MHsystem time descriptor according to the present invention;

FIG. 23 illustrates segmentation and encapsulation processes of aservice map table according to the present invention; and

FIG. 24 illustrates a flow chart for accessing a virtual channel usingFIC and SMT according to the present invention;

FIG. 25 is a view showing a protocol stack of an MH system according toanother embodiment of the present invention;

FIG. 26 is a conceptual block diagram of an MH receiver according toanother embodiment of the present invention;

FIG. 27 is a view showing the structure of an RS frame including amultiplexed data packet according to another embodiment of the presentinvention;

FIG. 28 is a view showing the structure of an MH transport packet (MHTP) according to an embodiment of the present invention;

FIG. 29 is a view showing a process of packetizing sync layer packetsaccording to an embodiment of the present invention;

FIG. 30 is a view showing a process of packetizing sync layer packets inan MH transport layer according to an embodiment of the presentinvention;

FIGS. 31A and 31B are views showing the configuration of encrypted filedelivery protocol (FDP) and file delivery control protocol (FDCP)packets packetized in an MH transport layer according to an embodimentof the present invention;

FIG. 32 is a view showing the header of an MH transport packetassociated with FIGS. 31A and 31B;

FIG. 33 is a view showing IP datagram packets packetized and encryptedin an MH transport layer according to an embodiment of the presentinvention;

FIG. 34 is a view showing the header of the MH TP associated with FIG.33;

FIGS. 35A and 35B are views showing an encryption algorithm according toan embodiment of the present invention;

FIGS. 36A to 36B are views showing a decryption algorithm according toan embodiment of the present invention;

FIG. 37 is a view showing an initial counter value according to anembodiment of the present invention;

FIG. 38 is a view explaining a process of encrypting and decrypting aresidue data block according to an embodiment of the present invention;

FIG. 39 is a view showing the bitstream syntax of a service map tableaccording to another embodiment of the present invention;

FIG. 40 is a view showing the syntax of the bitstream ofMH_CA_descriptor( ) according to an embodiment of the present invention;

FIG. 41 is a view showing the structure of an RS frame to whichconditional access is applied, according to another embodiment of thepresent invention;

FIG. 42 is a view showing another embodiment of a service map table(SMT-MH) configured by the structure of FIG. 41; and

FIGS. 43 to 45 are flowcharts illustrating a process of extracting dataaccording to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts. In addition,although the terms used in the present invention are selected fromgenerally known and used terms, some of the terms mentioned in thedescription of the present invention have been selected by the applicantat his or her discretion, the detailed meanings of which are describedin relevant parts of the description herein. Furthermore, it is requiredthat the present invention is understood, not simply by the actual termsused but by the meaning of each term lying within.

Among the terms used in the description of the present invention, mainservice data correspond to data that can be received by a fixedreceiving system and may include audio/video (A/V) data. Morespecifically, the main service data may include A/V data of highdefinition (HD) or standard definition (SD) levels and may also includediverse data types required for data broadcasting. Also, the known datacorrespond to data pre-known in accordance with a pre-arranged agreementbetween the receiving system and the transmitting system. Additionally,among the terms used in the present invention, “MH” corresponds to theinitials of “mobile” and “handheld” and represents the opposite conceptof a fixed-type system. Furthermore, the MH service data may include atleast one of mobile service data and handheld service data, and willalso be referred to as “mobile service data” for simplicity. Herein, themobile service data not only correspond to MH service data but may alsoinclude any type of service data with mobile or portablecharacteristics. Therefore, the mobile service data according to thepresent invention are not limited only to the MH service data.

The above-described mobile service data may correspond to data havinginformation, such as program execution files, stock information, and soon, and may also correspond to A/V data. Most particularly, the mobileservice data may correspond to A/V data having lower resolution andlower data rate as compared to the main service data. For example, if anA/V codec that is used for a conventional main service corresponds to aMPEG-2 codec, a MPEG-4 advanced video coding (AVC) or scalable videocoding (SVC) having better image compression efficiency may be used asthe A/V codec for the mobile service. Furthermore, any type of data maybe transmitted as the mobile service data. For example, transportprotocol expert group (TPEG) data for broadcasting real-timetransportation information may be transmitted as the main service data.

Also, a data service using the mobile service data may include weatherforecast services, traffic information services, stock informationservices, viewer participation quiz programs, real-time polls andsurveys, interactive education broadcast programs, gaming services,services providing information on synopsis, character, background music,and filming sites of soap operas or series, services providinginformation on past match scores and player profiles and achievements,and services providing information on product information and programsclassified by service, medium, time, and theme enabling purchase ordersto be processed. Herein, the present invention is not limited only tothe services mentioned above. In the present invention, the transmittingsystem provides backward compatibility in the main service data so as tobe received by the conventional receiving system. Herein, the mainservice data and the mobile service data are multiplexed to the samephysical channel and then transmitted.

Furthermore, the digital broadcast transmitting system according to thepresent invention performs additional encoding on the mobile servicedata and inserts the data already known by the receiving system andtransmitting system (e.g., known data), thereby transmitting theprocessed data. Therefore, when using the transmitting system accordingto the present invention, the receiving system may receive the mobileservice data during a mobile state and may also receive the mobileservice data with stability despite various distortion and noiseoccurring within the channel.

Receiving System

FIG. 1 illustrates a block diagram showing a general structure of adigital broadcasting receiving system according to an embodiment of thepresent invention. The digital broadcast receiving system according tothe present invention includes a baseband processor 100, a managementprocessor 200, and a presentation processor 300. The baseband processor100 includes an operation controller 110, a tuner 120, a demodulator130, an equalizer 140, a known sequence detector (or known datadetector) 150, a block decoder (or mobile handheld block decoder) 160, aprimary Reed-Solomon (RS) frame decoder 170, a secondary RS framedecoder 180, and a signaling decoder 190. The operation controller 110controls the operation of each block included in the baseband processor100.

By tuning the receiving system to a specific physical channel frequency,the tuner 120 enables the receiving system to receive main service data,which correspond to broadcast signals for fixed-type broadcast receivingsystems, and mobile service data, which correspond to broadcast signalsfor mobile broadcast receiving systems. At this point, the tunedfrequency of the specific physical channel is down-converted to anintermediate frequency (IF) signal, thereby being outputted to thedemodulator 130 and the known sequence detector 150. The passbanddigital IF signal being outputted from the tuner 120 may only includemain service data, or only include mobile service data, or include bothmain service data and mobile service data.

The demodulator 130 performs self-gain control, carrier wave recovery,and timing recovery processes on the passband digital IF signal inputtedfrom the tuner 120, thereby modifying the IF signal to a basebandsignal. Then, the demodulator 130 outputs the baseband signal to theequalizer 140 and the known sequence detector 150. The demodulator 130uses the known data symbol sequence inputted from the known sequencedetector 150 during the timing and/or carrier wave recovery, therebyenhancing the demodulating performance. The equalizer 140 compensateschannel-associated distortion included in the signal demodulated by thedemodulator 130. Then, the equalizer 140 outputs thedistortion-compensated signal to the block decoder 160. By using a knowndata symbol sequence inputted from the known sequence detector 150, theequalizer 140 may enhance the equalizing performance. Furthermore, theequalizer 140 may receive feed-back on the decoding result from theblock decoder 160, thereby enhancing the equalizing performance.

The known sequence detector 150 detects known data place (or position)inserted by the transmitting system from the input/output data (i.e.,data prior to being demodulated or data being processed with partialdemodulation). Then, the known sequence detector 150 outputs thedetected known data position information and known data sequencegenerated from the detected position information to the demodulator 130and the equalizer 140. Additionally, in order to allow the block decoder160 to identify the mobile service data that have been processed withadditional encoding by the transmitting system and the main service datathat have not been processed with any additional encoding, the knownsequence detector 150 outputs such corresponding information to theblock decoder 160.

If the data channel-equalized by the equalizer 140 and inputted to theblock decoder 160 correspond to data processed with both block-encodingand trellis-encoding by the transmitting system (i.e., data within theRS frame, signaling data), the block decoder 160 may performtrellis-decoding and block-decoding as inverse processes of thetransmitting system. On the other hand, if the data channel-equalized bythe equalizer 140 and inputted to the block decoder 160 correspond todata processed only with trellis-encoding and not block-encoding by thetransmitting system (i.e., main service data), the block decoder 160 mayperform only trellis-decoding.

The signaling decoder 190 decoded signaling data that have beenchannel-equalized and inputted from the equalizer 140. It is assumedthat the signaling data inputted to the signaling decoder 190 correspondto data processed with both block-encoding and trellis-encoding by thetransmitting system. Examples of such signaling data may includetransmission parameter channel (TPC) data and fast information channel(FIC) data. Each type of data will be described in more detail in alater process. The FIC data decoded by the signaling decoder 190 areoutputted to the FIC handler 215. And, the TPC data decoded by thesignaling decoder 190 are outputted to the TPC handler 214.

Meanwhile, according to the present invention, the transmitting systemuses RS frames by encoding units. Herein, the RS frame may be dividedinto a primary RS frame and a secondary RS frame. However, according tothe embodiment of the present invention, the primary RS frame and thesecondary RS frame will be divided based upon the level of importance ofthe corresponding data. The primary RS frame decoder 170 receives thedata outputted from the block decoder 160. At this point, according tothe embodiment of the present invention, the primary RS frame decoder170 receives only the mobile service data that have been Reed-Solomon(RS)-encoded and/or cyclic redundancy check (CRC)-encoded from the blockdecoder 160.

Herein, the primary RS frame decoder 170 receives only the mobileservice data and not the main service data. The primary RS frame decoder170 performs inverse processes of an RS frame encoder (not shown)included in the digital broadcast transmitting system, therebycorrecting errors existing within the primary RS frame. Morespecifically, the primary RS frame decoder 170 forms a primary RS frameby grouping a plurality of data groups and, then, correct errors inprimary RS frame units. In other words, the primary RS frame decoder 170decodes primary RS frames, which are being transmitted for actualbroadcast services.

Additionally, the secondary RS frame decoder 180 receives the dataoutputted from the block decoder 160. At this point, according to theembodiment of the present invention, the secondary RS frame decoder 180receives only the mobile service data that have been RS-encoded and/orCRC-encoded from the block decoder 160. Herein, the secondary RS framedecoder 180 receives only the mobile service data and not the mainservice data. The secondary RS frame decoder 180 performs inverseprocesses of an RS frame encoder (not shown) included in the digitalbroadcast transmitting system, thereby correcting errors existing withinthe secondary RS frame. More specifically, the secondary RS framedecoder 180 forms a secondary RS frame by grouping a plurality of datagroups and, then, correct errors in secondary RS frame units. In otherwords, the secondary RS frame decoder 180 decodes secondary RS frames,which are being transmitted for mobile audio service data, mobile videoservice data, guide data, and so on.

Meanwhile, the management processor 200 according to an embodiment ofthe present invention includes an MH physical adaptation processor 210,an IP network stack 220, a streaming handler 230, a system information(SI) handler 240, a file handler 250, a multi-purpose internet mainextensions (MIME) type handler 260, and an electronic service guide(ESG) handler 270, and an ESG decoder 280, and a storage unit 290. TheMH physical adaptation processor 210 includes a primary RS frame handler211, a secondary RS frame handler 212, an MH transport packet (TP)handler 213, a TPC handler 214, an FIC handler 215, and a physicaladaptation control signal handler 216. The TPC handler 214 receives andprocesses baseband information required by modules corresponding to theMH physical adaptation processor 210. The baseband information isinputted in the form of TPC data. Herein, the TPC handler 214 uses thisinformation to process the FIC data, which have been sent from thebaseband processor 100.

The TPC data are transmitted from the transmitting system to thereceiving system via a predetermined region of a data group. The TPCdata may include at least one of an MH ensemble ID, an MH sub-framenumber, a total number of MH groups (TNoG), an RS frame continuitycounter, a column size of RS frame (N), and an FIC version number.Herein, the MH ensemble ID indicates an identification number of each MHensemble carried in the corresponding channel. The MH sub-frame numbersignifies a number identifying the MH sub-frame number in an MH frame,wherein each MH group associated with the corresponding MH ensemble istransmitted. The TNoG represents the total number of MH groups includingall of the MH groups belonging to all MH parades included in an MHsub-frame. The RS frame continuity counter indicates a number thatserves as a continuity counter of the RS frames carrying thecorresponding MH ensemble. Herein, the value of the RS frame continuitycounter shall be incremented by 1 modulo 16 for each successive RSframe. N represents the column size of an RS frame belonging to thecorresponding MH ensemble. Herein, the value of N determines the size ofeach MH TP. Finally, the FIC version number signifies the version numberof an FIC body carried on the corresponding physical channel.

As described above, diverse TPC data are inputted to the TPC handler 214via the signaling decoder 190 shown in FIG. 1. Then, the received TPCdata are processed by the TPC handler 214. The received TPC data mayalso be used by the FIC handler 215 in order to process the FIC data.The FIC handler 215 processes the FIC data by associating the FIC datareceived from the baseband processor 100 with the TPC data. The physicaladaptation control signal handler 216 collects FIC data received throughthe FIC handler 215 and SI data received through RS frames. Then, thephysical adaptation control signal handler 216 uses the collected FICdata and SI data to configure and process IP datagrams and accessinformation of mobile broadcast services. Thereafter, the physicaladaptation control signal handler 216 stores the processed IP datagramsand access information to the storage unit 290.

The primary RS frame handler 211 identifies primary RS frames receivedfrom the primary RS frame decoder 170 of the baseband processor 100 foreach row unit, so as to configure an MH TP. Thereafter, the primary RSframe handler 211 outputs the configured MH TP to the MH TP handler 213.The secondary RS frame handler 212 identifies secondary RS framesreceived from the secondary RS frame decoder 180 of the basebandprocessor 100 for each row unit, so as to configure an MH TP.Thereafter, the secondary RS frame handler 212 outputs the configured MHTP to the MH TP handler 213. The MH transport packet (TP) handler 213extracts a header from each MH TP received from the primary RS framehandler 211 and the secondary RS frame handler 212, thereby determiningthe data included in the corresponding MH TP. Then, when the determineddata correspond to SI data (i.e., SI data that are not encapsulated toIP datagrams), the corresponding data are outputted to the physicaladaptation control signal handler 216. Alternatively, when thedetermined data correspond to an IP datagram, the corresponding data areoutputted to the IP network stack 220.

The IP network stack 220 processes broadcast data that are beingtransmitted in the form of IP datagrams. More specifically, the IPnetwork stack 220 processes data that are inputted via user datagramprotocol (UDP), real-time transport protocol (RTP), real-time transportcontrol protocol (RTCP), asynchronous layered coding/layered codingtransport (ALC/LCT), file delivery over unidirectional transport(FLUTE), and so on. Herein, when the processed data correspond tostreaming data, the corresponding data are outputted to the streaminghandler 230. And, when the processed data correspond to data in a fileformat, the corresponding data are outputted to the file handler 250.Finally, when the processed data correspond to SI-associated data, thecorresponding data are outputted to the SI handler 240.

The SI handler 240 receives and processes SI data having the form of IPdatagrams, which are inputted to the IP network stack 220. When theinputted data associated with SI correspond to MIME-type data, theinputted data are outputted to the MIME-type handler 260. The MIME-typehandler 260 receives the MIME-type SI data outputted from the SI handler240 and processes the received MIME-type SI data. The file handler 250receives data from the IP network stack 220 in an object format inaccordance with the ALC/LCT and FLUTE structures. The file handler 250groups the received data to create a file format. Herein, when thecorresponding file includes ESG, the file is outputted to the ESGhandler 270. On the other hand, when the corresponding file includesdata for other file-based services, the file is outputted to thepresentation controller 330 of the presentation processor 300.

The ESG handler 270 processes the ESG data received from the filehandler 250 and stores the processed ESG data to the storage unit 290.Alternatively, the ESG handler 270 may output the processed ESG data tothe ESG decoder 280, thereby allowing the ESG data to be used by the ESGdecoder 280. The storage unit 290 stores the system information (SI)received from the physical adaptation control signal handler 210 and theESG handler 270 therein. Thereafter, the storage unit 290 transmits thestored SI data to each block.

The ESG decoder 280 either recovers the ESG data and SI data stored inthe storage unit 290 or recovers the ESG data transmitted from the ESGhandler 270. Then, the ESG decoder 280 outputs the recovered data to thepresentation controller 330 in a format that can be outputted to theuser. The streaming handler 230 receives data from the IP network stack220, wherein the format of the received data are in accordance with RTPand/or RTCP structures. The streaming handler 230 extracts audio/videostreams from the received data, which are then outputted to theaudio/video (A/V) decoder 310 of the presentation processor 300. Theaudio/video decoder 310 then decodes each of the audio stream and videostream received from the streaming handler 230.

The display module 320 of the presentation processor 300 receives audioand video signals respectively decoded by the A/V decoder 310. Then, thedisplay module 320 provides the received audio and video signals to theuser through a speaker and/or a screen. The presentation controller 330corresponds to a controller managing modules that output data receivedby the receiving system to the user. The channel service manager 340manages an interface with the user, which enables the user to usechannel-based broadcast services, such as channel map management,channel service connection, and so on. The application manager 350manages an interface with a user using ESG display or other applicationservices that do not correspond to channel-based services.

Data Format Structure

Meanwhile, the data structure used in the mobile broadcasting technologyaccording to the embodiment of the present invention may include a datagroup structure and an RS frame structure, which will now be describedin detail. FIG. 2 illustrates an exemplary structure of a data groupaccording to the present invention. FIG. 2 shows an example of dividinga data group according to the data structure of the present inventioninto 10 MH blocks (i.e., MH block 1 (B1) to MH block 10 (B10)). In thisexample, each MH block has the length of 16 segments. Referring to FIG.2, only the RS parity data are allocated to portions of the first 5segments of the MH block 1 (B1) and the last 5 segments of the MH block10 (B10). The RS parity data are excluded in regions A to D of the datagroup. More specifically, when it is assumed that one data group isdivided into regions A, B, C, and D, each MH block may be included inany one of region A to region D depending upon the characteristic ofeach MH block within the data group.

Herein, the data group is divided into a plurality of regions to be usedfor different purposes. More specifically, a region of the main servicedata having no interference or a very low interference level may beconsidered to have a more resistant (or stronger) receiving performanceas compared to regions having higher interference levels. Additionally,when using a system inserting and transmitting known data in the datagroup, wherein the known data are known based upon an agreement betweenthe transmitting system and the receiving system, and when consecutivelylong known data are to be periodically inserted in the mobile servicedata, the known data having a predetermined length may be periodicallyinserted in the region having no interference from the main service data(i.e., a region wherein the main service data are not mixed). However,due to interference from the main service data, it is difficult toperiodically insert known data and also to insert consecutively longknown data to a region having interference from the main service data.

Referring to FIG. 2, MH block 4 (B4) to MH block 7 (B7) correspond toregions without interference of the main service data. MH block 4 (B4)to MH block 7 (B7) within the data group shown in FIG. 2 correspond to aregion where no interference from the main service data occurs. In thisexample, a long known data sequence is inserted at both the beginningand end of each MH block. In the description of the present invention,the region including MH block 4 (B4) to MH block 7 (B7) will be referredto as “region A (=B4+B5+B6+B7)”. As described above, when the data groupincludes region A having a long known data sequence inserted at both thebeginning and end of each MH block, the receiving system is capable ofperforming equalization by using the channel information that can beobtained from the known data. Therefore, the strongest equalizingperformance may be yielded (or obtained) from one of region A to regionD.

In the example of the data group shown in FIG. 2, MH block 3 (B3) and MHblock 8 (B8) correspond to a region having little interference from themain service data. Herein, a long known data sequence is inserted inonly one side of each MH block B3 and B8. More specifically, due to theinterference from the main service data, a long known data sequence isinserted at the end of MH block 3 (B3), and another long known datasequence is inserted at the beginning of MH block 8 (B8). In the presentinvention, the region including MH block 3 (B3) and MH block 8 (B8) willbe referred to as “region B (=B3+B8)”. As described above, when the datagroup includes region B having a long known data sequence inserted atonly one side (beginning or end) of each MH block, the receiving systemis capable of performing equalization by using the channel informationthat can be obtained from the known data. Therefore, a strongerequalizing performance as compared to region C/D may be yielded (orobtained).

Referring to FIG. 2, MH block 2 (B2) and MH block 9 (B9) correspond to aregion having more interference from the main service data as comparedto region B. A long known data sequence cannot be inserted in any sideof MH block 2 (B2) and MH block 9 (B9). Herein, the region including MHblock 2 (B2) and MH block 9 (B9) will be referred to as “region C(=B2+B9)”. Finally, in the example shown in FIG. 2, MH block 1 (B1) andMH block 10 (B10) correspond to a region having more interference fromthe main service data as compared to region C. Similarly, a long knowndata sequence cannot be inserted in any side of MH block 1 (B1) and MHblock 10 (B10). Herein, the region including MH block 1 (B1) and MHblock 10 (B10) will be referred to as “region D (=B1+B10)”. Since regionC/D is spaced further apart from the known data sequence, when thechannel environment undergoes frequent and abrupt changes, the receivingperformance of region C/D may be deteriorated.

Additionally, the data group includes a signaling information areawherein signaling information is assigned (or allocated). In the presentinvention, the signaling information area may start from the 1^(st)segment of the 4^(th) MH block (B4) to a portion of the 2^(nd) segment.According to an embodiment of the present invention, the signalinginformation area for inserting signaling information may start from the1^(st) segment of the 4^(th) MH block (B4) to a portion of the 2^(nd)segment. More specifically, 276(=207+69) bytes of the 4^(th) MH block(B4) in each data group are assigned as the signaling information area.In other words, the signaling information area consists of 207 bytes ofthe 1^(st) segment and the first 69 bytes of the 2^(nd) segment of the4^(th) MH block (B4). The 1^(st) segment of the 4^(th) MH block (B4)corresponds to the 17^(th) or 173^(rd) segment of a VSB field.

Herein, the signaling information may be identified by two differenttypes of signaling channels: a transmission parameter channel (TPC) anda fast information channel (FIC). Herein, the TPC data may include atleast one of an MH ensemble ID, an MH sub-frame number, a total numberof MH groups (TNoG), an RS frame continuity counter, a column size of RSframe (N), and an FIC version number. However, the TPC data (orinformation) presented herein are merely exemplary. And, since theadding or deleting of signaling information included in the TPC data maybe easily adjusted and modified by one skilled in the art, the presentinvention will, therefore, not be limited to the examples set forthherein. Furthermore, the FIC is provided to enable a fast serviceacquisition of data receivers, and the FIC includes cross layerinformation between the physical layer and the upper layer(s).

For example, when the data group includes 6 known data sequences, asshown in FIG. 2, the signaling information area is located between thefirst known data sequence and the second known data sequence. Morespecifically, the first known data sequence is inserted in the last 2segments of the 3^(rd) MH block (B3), and the second known data sequencein inserted in the 2^(nd) and 3^(rd) segments of the 4^(th) MH block(B4). Furthermore, the 3^(rd) to 6^(th) known data sequences arerespectively inserted in the last 2 segments of each of the 4^(th),5^(th), 6^(th), and 7^(th) MH blocks (B4, B5, B6, and B7). The 1^(st)and 3^(rd) to 6^(th) known data sequences are spaced apart by 16segments.

Hereinafter, transmission/reception of service data having a formatdifferent from the existing MH format in an MH system according toanother embodiment of the present invention will be described. At thistime, the service having the different format includes a MediaFLO™service for providing a mobile broadcasting service of a subscriptionbase via a single physical channel. Hereinafter, for convenience ofdescription, for example, the MediaFLO™ service will be described, butthe present invention is not limited thereto.

FIG. 3 illustrates an RS frame according to an embodiment of the presentinvention. The RS frame shown in FIG. 3 corresponds to a collection ofone or more data groups. The RS frame is received for each MH frame in acondition where the receiving system receives the FIC and processes thereceived FIC and where the receiving system is switched to atime-slicing mode so that the receiving system can receive MH ensemblesincluding ESG entry points. Each RS frame includes IP streams of eachservice or ESG, and SMT section data may exist in all RS frames. The RSframe according to the embodiment of the present invention consists ofat least one MH transport packet (TP). Herein, the MH TP includes an MHheader and an MH payload.

The MH payload may include mobile service data as well as signalingdata. More specifically, an MH payload may include only mobile servicedata, or may include only signaling data, or may include both mobileservice data and signaling data. According to the embodiment of thepresent invention, the MH header may identify (or distinguish) the datatypes included in the MH payload. More specifically, when the MH TPincludes a first MH header, this indicates that the MH payload includesonly the signaling data. Also, when the MH TP includes a second MHheader, this indicates that the MH payload includes both the signalingdata and the mobile service data. Finally, when MH TP includes a thirdMH header, this indicates that the MH payload includes only the mobileservice data. In the example shown in FIG. 3, the RS frame is assignedwith IP datagrams (IP datagram 1 and IP datagram 2) for two servicetypes.

Data Transmission Structure

FIG. 4 illustrates a structure of a MH frame for transmitting andreceiving mobile service data according to the present invention. In theexample shown in FIG. 4, one MH frame consists of 5 sub-frames, whereineach sub-frame includes 16 slots. In this case, the MH frame accordingto the present invention includes 5 sub-frames and 80 slots. Also, in apacket level, one slot is configured of 156 data packets (i.e.,transport stream packets), and in a symbol level, one slot is configuredof 156 data segments. Herein, the size of one slot corresponds to onehalf (½) of a VSB field. More specifically, since one 207-byte datapacket has the same amount of data as a data segment, a data packetprior to being interleaved may also be used as a data segment. At thispoint, two VSB fields are grouped to form a VSB frame.

FIG. 5 illustrates an exemplary structure of a VSB frame, wherein oneVSB frame consists of 2 VSB fields (i.e., an odd field and an evenfield). Herein, each VSB field includes a field synchronization segmentand 312 data segments. The slot corresponds to a basic time unit formultiplexing the mobile service data and the main service data. Herein,one slot may either include the mobile service data or be configuredonly of the main service data. If the first 118 data packets within theslot correspond to a data group, the remaining 38 data packets becomethe main service data packets. In another example, when no data groupexists in a slot, the corresponding slot is configured of 156 mainservice data packets. Meanwhile, when the slots are assigned to a VSBframe, an off-set exists for each assigned position.

FIG. 6 illustrates a mapping example of the positions to which the first4 slots of a sub-frame are assigned with respect to a VSB frame in aspatial area. And, FIG. 7 illustrates a mapping example of the positionsto which the first 4 slots of a sub-frame are assigned with respect to aVSB frame in a chronological (or time) area. Referring to FIG. 6 andFIG. 7, a 38^(th) data packet (TS packet #37) of a 1^(st) slot (Slot #0)is mapped to the 1^(st) data packet of an odd VSB field. A 38^(th) datapacket (TS packet #37) of a 2^(nd) slot (Slot #1) is mapped to the157^(th) data packet of an odd VSB field. Also, a 38^(th) data packet(TS packet #37) of a 3^(rd) slot (Slot #2) is mapped to the 1^(st) datapacket of an even VSB field. And, a 38^(th) data packet (TS packet #37)of a 4^(th) slot (Slot #3) is mapped to the 157^(th) data packet of aneven VSB field. Similarly, the remaining 12 slots within thecorresponding sub-frame are mapped in the subsequent VSB frames usingthe same method.

FIG. 8 illustrates an exemplary assignment order of data groups beingassigned to one of 5 sub-frames, wherein the 5 sub-frames configure anMH frame. For example, the method of assigning data groups may beidentically applied to all MH frames or differently applied to each MHframe. Furthermore, the method of assigning data groups may beidentically applied to all sub-frames or differently applied to eachsub-frame. At this point, when it is assumed that the data groups areassigned using the same method in all sub-frames of the corresponding MHframe, the total number of data groups being assigned to an MH frame isequal to a multiple of ‘5’. According to the embodiment of the presentinvention, a plurality of consecutive data groups is assigned to bespaced as far apart from one another as possible within the MH frame.Thus, the system can be capable of responding promptly and effectivelyto any burst error that may occur within a sub-frame.

For example, when it is assumed that 3 data groups are assigned to asub-frame, the data groups are assigned to a 1^(st) slot (Slot #0), a5^(th) slot (Slot #4), and a 9^(th) slot (Slot #8) in the sub-frame,respectively. FIG. 8 illustrates an example of assigning 16 data groupsin one sub-frame using the above-described pattern (or rule). In otherwords, each data group is serially assigned to 16 slots corresponding tothe following numbers: 0, 8, 4, 12, 1, 9, 5, 13, 2, 10, 6, 14, 3, 11, 7,and 15. Equation 1 below shows the above-described rule (or pattern) forassigning data groups in a sub-frame.

j=(4i+0)mod 16  Equation 1

Herein, 0=0 if i<4,

-   -   0=2 else if i<8,    -   0=1 else if i<12,    -   0=3 else.

Herein, j indicates the slot number within a sub-frame. The value of jmay range from 0 to 15 (i.e., 0≦j≦15). Also, variable i indicates thedata group number. The value of i may range from 0 to 15 (i.e., 0≦i≦15).

In the present invention, a collection of data groups included in a MHframe will be referred to as a “parade”. Based upon the RS frame mode,the parade transmits data of at least one specific RS frame. The mobileservice data within one RS frame may be assigned either to all ofregions A/B/C/D within the corresponding data group, or to at least oneof regions A/B/C/D. In the embodiment of the present invention, themobile service data within one RS frame may be assigned either to all ofregions A/B/C/D, or to at least one of regions A/B and regions C/D. Ifthe mobile service data are assigned to the latter case (i.e., one ofregions A/B and regions C/D), the RS frame being assigned to regions A/Band the RS frame being assigned to regions C/D within the correspondingdata group are different from one another.

According to the embodiment of the present invention, the RS frame beingassigned to regions A/B within the corresponding data group will bereferred to as a “primary RS frame”, and the RS frame being assigned toregions C/D within the corresponding data group will be referred to as a“secondary RS frame”, for simplicity. Also, the primary RS frame and thesecondary RS frame form (or configure) one parade. More specifically,when the mobile service data within one RS frame are assigned either toall of regions A/B/C/D within the corresponding data group, one paradetransmits one RS frame. Conversely, when the mobile service data withinone RS frame are assigned either to at least one of regions A/B andregions C/D, one parade may transmit up to 2 RS frames. Morespecifically, the RS frame mode indicates whether a parade transmits oneRS frame, or whether the parade transmits two RS frames. Such RS framemode is transmitted as the above-described TPC data. Table 1 below showsan example of the RS frame mode.

TABLE 1 RS frame mode Description 00 There is only one primary RS framefor all group regions 01 There are two separate RS frames. Primary RSframe for group regions A and B Secondary RS frame for group regions Cand D 10 Reserved 11 Reserved

Table 1 illustrates an example of allocating 2 bits in order to indicatethe RS frame mode. For example, referring to Table 1, when the RS framemode value is equal to ‘00’, this indicates that one parade transmitsone RS frame. And, when the RS frame mode value is equal to ‘01’, thisindicates that one parade transmits two RS frames, i.e., the primary RSframe and the secondary RS frame. More specifically, when the RS framemode value is equal to ‘01’, data of the primary RS frame for regionsA/B are assigned and transmitted to regions A/B of the correspondingdata group. Similarly, data of the secondary RS frame for regions C/Dare assigned and transmitted to regions C/D of the corresponding datagroup.

As described in the assignment of data groups, the parades are alsoassigned to be spaced as far apart from one another as possible withinthe sub-frame. Thus, the system can be capable of responding promptlyand effectively to any burst error that may occur within a sub-frame.Furthermore, the method of assigning parades may be identically appliedto all MH frames or differently applied to each MH frame. According tothe embodiment of the present invention, the parades may be assigneddifferently for each MH frame and identically for all sub-frames withinan MH frame. More specifically, the MH frame structure may vary by MHframe units. Thus, an ensemble rate may be adjusted on a more frequentand flexible basis.

FIG. 9 illustrates an example of multiple data groups of a single paradebeing assigned (or allocated) to an MH frame. More specifically, FIG. 9illustrates an example of a plurality of data groups included in asingle parade, wherein the number of data groups included in a sub-frameis equal to ‘3’, being allocated to an MH frame. Referring to FIG. 9, 3data groups are sequentially assigned to a sub-frame at a cycle periodof 4 slots. Accordingly, when this process is equally performed in the 5sub-frames included in the corresponding MH frame, 15 data groups areassigned to a single MH frame. Herein, the 15 data groups correspond todata groups included in a parade. Therefore, since one sub-frame isconfigured of 4 VSB frame, and since 3 data groups are included in asub-frame, the data group of the corresponding parade is not assigned toone of the 4 VSB frames within a sub-frame.

For example, when it is assumed that one parade transmits one RS frame,and that a RS frame encoder (not shown) included in the transmittingsystem performs RS-encoding on the corresponding RS frame, therebyadding 24 bytes of parity data to the corresponding RS frame andtransmitting the processed RS frame, the parity data occupyapproximately 11.37% (=24/(187+24)×100) of the total code word length.Meanwhile, when one sub-frame includes 3 data groups, and when the datagroups included in the parade are assigned, as shown in FIG. 9, a totalof 15 data groups form an RS frame. Accordingly, even when an erroroccurs in an entire data group due to a burst noise within a channel,the percentile is merely 6.67% (=1/15×100). Therefore, the receivingsystem may correct all errors by performing an erasure RS decodingprocess. More specifically, when the erasure RS decoding is performed, anumber of channel errors corresponding to the number of RS parity bytesmay be corrected. By doing so, the receiving system may correct theerror of at least one data group within one parade. Thus, the minimumburst noise length correctable by a RS frame is over 1 VSB frame.

Meanwhile, when data groups of a parade are assigned as shown in FIG. 9,either main service data may be assigned between each data group, ordata groups corresponding to different parades may be assigned betweeneach data group. More specifically, data groups corresponding tomultiple parades may be assigned to one MH frame. Basically, the methodof assigning data groups corresponding to multiple parades is verysimilar to the method of assigning data groups corresponding to a singleparade. In other words, data groups included in other parades that areto be assigned to an MH frame are also respectively assigned accordingto a cycle period of 4 slots. At this point, data groups of a differentparade may be sequentially assigned to the respective slots in acircular method. Herein, the data groups are assigned to slots startingfrom the ones to which data groups of the previous parade have not yetbeen assigned. For example, when it is assumed that data groupscorresponding to a parade are assigned as shown in FIG. 9, data groupscorresponding to the next parade may be assigned to a sub-frame startingeither from the 12^(th) slot of a sub-frame. However, this is merelyexemplary. In another example, the data groups of the next parade mayalso be sequentially assigned to a different slot within a sub-frame ata cycle period of 4 slots starting from the 3^(rd) slot.

FIG. 10 illustrates an example of transmitting 3 parades (Parade #0,Parade #1, and Parade #2) to an MH frame. More specifically, FIG. 10illustrates an example of transmitting parades included in one of 5sub-frames, wherein the 5 sub-frames configure one MH frame. When the1^(st) parade (Parade #0) includes 3 data groups for each sub-frame, thepositions of each data groups within the sub-frames may be obtained bysubstituting values ‘0’ to ‘2’ for i in Equation 1. More specifically,the data groups of the 1^(st) parade (Parade #0) are sequentiallyassigned to the 1^(st), 5^(th), and 9^(th) slots (Slot #0, Slot #4, andSlot #8) within the sub-frame. Also, when the 2^(nd) parade includes 2data groups for each sub-frame, the positions of each data groups withinthe sub-frames may be obtained by substituting values ‘3’ and ‘4’ for iin Equation 1. More specifically, the data groups of the 2^(nd) parade(Parade #1) are sequentially assigned to the 2^(nd) and 12^(th) slots(Slot #3 and Slot #11) within the sub-frame. Finally, when the 3^(rd)parade includes 2 data groups for each sub-frame, the positions of eachdata groups within the sub-frames may be obtained by substituting values‘5’ and ‘6’ for i in Equation 1. More specifically, the data groups ofthe 3^(rd) parade (Parade #2) are sequentially assigned to the 7^(th)and 11^(th) slots (Slot #6 and Slot #10) within the sub-frame.

As described above, data groups of multiple parades may be assigned to asingle MH frame, and, in each sub-frame, the data groups are seriallyallocated to a group space having 4 slots from left to right. Therefore,a number of groups of one parade per sub-frame (NoG) may correspond toany one integer from ‘1’ to ‘8’. Herein, since one MH frame includes 5sub-frames, the total number of data groups within a parade that can beallocated to an MH frame may correspond to any one multiple of ‘5’ranging from ‘5’ to ‘40’.

FIG. 11 illustrates an example of expanding the assignment process of 3parades, shown in FIG. 10, to 5 sub-frames within an MH frame. FIG. 12illustrates a data transmission structure according to an embodiment ofthe present invention, wherein signaling data are included in a datagroup so as to be transmitted. As described above, an MH frame isdivided into 5 sub-frames. Data groups corresponding to a plurality ofparades co-exist in each sub-frame. Herein, the data groupscorresponding to each parade are grouped by MH frame units, therebyconfiguring a single parade.

The data structure shown in FIG. 12 includes 3 parades, one ESGdedicated channel (EDC) parade (i.e., parade with NoG=1), and 2 serviceparades (i.e., parade with NoG=4 and parade with NoG=3). Also, apredetermined portion of each data group (i.e., 37 bytes/data group) isused for delivering (or sending) FIC information associated with mobileservice data, wherein the FIC information is separately encoded from theRS-encoding process. The FIC region assigned to each data group consistsof one FIC segments. Herein, each segment is interleaved by MH sub-frameunits, thereby configuring an FIC body, which corresponds to a completedFIC transmission structure. However, whenever required, each segment maybe interleaved by MH frame units and not by MH sub-frame units, therebybeing completed in MH frame units.

Meanwhile, the concept of an MH ensemble is applied in the embodiment ofthe present invention, thereby defining a collection (or group) ofservices. Each MH ensemble carries the same QoS and is coded with thesame FEC code. Also, each MH ensemble has the same unique identifier(i.e., ensemble ID) and corresponds to consecutive RS frames. As shownin FIG. 12, the FIC segment corresponding to each data group describedservice information of an MH ensemble to which the corresponding datagroup belongs. When FIC segments within a sub-frame are grouped anddeinterleaved, all service information of a physical channel throughwhich the corresponding FICs are transmitted may be obtained. Therefore,the receiving system may be able to acquire the channel information ofthe corresponding physical channel, after being processed with physicalchannel tuning, during a sub-frame period. Furthermore, FIG. 12illustrates a structure further including a separate EDC parade apartfrom the service parade and wherein electronic service guide (ESG) dataare transmitted in the 1^(st) slot of each sub-frame.

Hierarchical Signaling Structure

FIG. 13 illustrates a hierarchical signaling structure according to anembodiment of the present invention. As shown in FIG. 13, the mobilebroadcasting technology according to the embodiment of the presentinvention adopts a signaling method using FIC and SMT. In thedescription of the present invention, the signaling structure will bereferred to as a hierarchical signaling structure. Hereinafter, adetailed description on how the receiving system accesses a virtualchannel via FIC and SMT will now be given with reference to FIG. 13. TheFIC body defined in an MH transport (M1) identifies the physicallocation of each the data stream for each virtual channel and providesvery high level descriptions of each virtual channel. Being MH ensemblelevel signaling information, the service map table (SMT) provides MHensemble level signaling information. The SMT provides the IP accessinformation of each virtual channel belonging to the respective MHensemble within which the SMT is carried. The SMT also provides all IPstream component level information required for the virtual channelservice acquisition.

Referring to FIG. 13, each MH ensemble (i.e., Ensemble 0, Ensemble 1, .. . , Ensemble K) includes a stream information on each associated (orcorresponding) virtual channel (e.g., virtual channel 0 IP stream,virtual channel 1 IP stream, and virtual channel 2 IP stream). Forexample, Ensemble 0 includes virtual channel 0 IP stream and virtualchannel 1 IP stream. And, each MH ensemble includes diverse informationon the associated virtual channel (i.e., Virtual Channel 0 Table Entry,Virtual Channel 0 Access Info, Virtual Channel 1 Table Entry, VirtualChannel 1 Access Info, Virtual Channel 2 Table Entry, Virtual Channel 2Access Info, Virtual Channel N Table Entry, Virtual Channel N AccessInfo, and so on). The FIC body payload includes information on MHensembles (e.g., ensemble_id field, and referred to as “ensemblelocation” in FIG. 13) and information on a virtual channel associatedwith the corresponding MH ensemble (e.g., when such informationcorresponds to a major_channel_num field and a minor_channel_num field,the information is expressed as Virtual Channel 0, Virtual Channel 1, .. . , Virtual Channel N in FIG. 13).

The application of the signaling structure in the receiving system willnow be described in detail. When a user selects a channel he or shewishes to view (hereinafter, the user-selected channel will be referredto as “channel θ” for simplicity), the receiving system first parses thereceived FIC. Then, the receiving system acquires information on an MHensemble (i.e., ensemble location), which is associated with the virtualchannel corresponding to channel θ (hereinafter, the corresponding MHensemble will be referred to as “MH ensemble θ” for simplicity). Byacquiring slots only corresponding to the MH ensemble θ using thetime-slicing method, the receiving system configures ensemble θ. Theensemble θ configured as described above, includes an SMT on theassociated virtual channels (including channel θ) and IP streams on thecorresponding virtual channels. Therefore, the receiving system uses theSMT included in the MH ensemble θ in order to acquire variousinformation on channel θ (e.g., Virtual Channel θ Table Entry) andstream access information on channel θ (e.g., Virtual Channel θ AccessInfo). The receiving system uses the stream access information onchannel θ to receive only the associated IP streams, thereby providingchannel θ services to the user.

Fast Information Channel (FIC)

The digital broadcast receiving system according to the presentinvention adopts the fast information channel (FIC) for a faster accessto a service that is currently being broadcasted. More specifically, theFIC handler 215 of FIG. 1 parses the FIC body, which corresponds to anFIC transmission structure, and outputs the parsed result to thephysical adaptation control signal handler 216. FIG. 14 illustrates anexemplary FIC body format according to an embodiment of the presentinvention. According to the embodiment of the present invention, the FICformat consists of an FIC body header and an FIC body payload.

Meanwhile, according to the embodiment of the present invention, dataare transmitted through the FIC body header and the FIC body payload inFIC segment units. Each FIC segment has the size of 37 bytes, and eachFIC segment consists of a 2-byte FIC segment header and a 35-byte FICsegment payload. More specifically, an FIC body configured of an FICbody header and an FIC body payload is segmented in units of 35 databytes, which are then carried in at least one FIC segment within the FICsegment payload, so as to be transmitted. In the description of thepresent invention, an example of inserting one FIC segment in one datagroup, which is then transmitted, will be given. In this case, thereceiving system receives a slot corresponding to each data group byusing a time-slicing method.

The signaling decoder 190 included in the receiving system shown in FIG.1 collects each FIC segment inserted in each data group. Then, thesignaling decoder 190 uses the collected FIC segments to created asingle FIC body. Thereafter, the signaling decoder 190 performs adecoding process on the FIC body payload of the created FIC body, sothat the decoded FIC body payload corresponds to an encoded result of asignaling encoder (not shown) included in the transmitting system.Subsequently, the decoded FIC body payload is outputted to the FIChandler 215. The FIC handler 215 parses the FIC data included in the FICbody payload, and then outputs the parsed FIC data to the physicaladaptation control signal handler 216. The physical adaptation controlsignal handler 216 uses the inputted FIC data to perform processesassociated with MH ensembles, virtual channels, SMTs, and so on.

According to an embodiment of the present invention, when an FIC body issegmented, and when the size of the last segmented portion is smallerthan 35 data bytes, it is assumed that the lacking number of data bytesin the FIC segment payload is completed with by adding the same numberof stuffing bytes therein, so that the size of the last FIC segment canbe equal to 35 data bytes. However, it is apparent that theabove-described data byte values (i.e., 37 bytes for the FIC segment, 2bytes for the FIC segment header, and 35 bytes for the FIC segmentpayload) are merely exemplary, and will, therefore, not limit the scopeof the present invention.

FIG. 15 illustrates an exemplary bit stream syntax structure withrespect to an FIC segment according to an embodiment of the presentinvention. Herein, the FIC segment signifies a unit used fortransmitting the FIC data. The FIC segment consists of an FIC segmentheader and an FIC segment payload. Referring to FIG. 15, the FIC segmentpayload corresponds to the portion starting from the ‘for’ loopstatement. Meanwhile, the FIC segment header may include a FIC_typefield, an error_indicator field, an FIC_seg_number field, and anFIC_last_seg_number field. A detailed description of each field will nowbe given.

The FIC_type field is a 2-bit field indicating the type of thecorresponding FIC. The error_indicator field is a 1-bit field, whichindicates whether or not an error has occurred within the FIC segmentduring data transmission. If an error has occurred, the value of theerror_indicator field is set to ‘1’. More specifically, when an errorthat has failed to be recovered still remains during the configurationprocess of the FIC segment, the error_indicator field value is set to‘1’. The error_indicator field enables the receiving system to recognizethe presence of an error within the FIC data. The FIC_seg_number fieldis a 4-bit field. Herein, when a single FIC body is divided into aplurality of FIC segments and transmitted, the FIC_seg_number fieldindicates the number of the corresponding FIC segment. Finally, theFIC_last_seg_number field is also a 4-bit field. The FIC_last_seg_numberfield indicates the number of the last FIC segment within thecorresponding FIC body.

FIG. 16 illustrates an exemplary bit stream syntax structure withrespect to a payload of an FIC segment according to the presentinvention, when an FIC type field value is equal to ‘0’. According tothe embodiment of the present invention, the payload of the FIC segmentis divided into 3 different regions. A first region of the FIC segmentpayload exists only when the FIC_seg_number field value is equal to ‘0’.Herein, the first region may include a current_next_indicator field, anESG_version field, and a transport_stream_id field. However, dependingupon the embodiment of the present invention, it may be assumed thateach of the 3 fields exists regardless of the FIC_seg_number field.

The current_next_indicator field is a 16-bit field. Thecurrent_next_indicator field acts as an indicator identifying whetherthe corresponding FIC data carry MH ensemble configuration informationof an MH frame including the current FIC segment, or whether thecorresponding FIC data carry MH ensemble configuration information of anext MH frame. The ESG_version field is a 5-bit field indicating ESGversion information. Herein, by providing version information on theservice guide providing channel of the corresponding ESG, theESG_version field enables the receiving system to notify whether or notthe corresponding ESG has been updated. Finally, the transport_stream_idfield is a 16-bit field acting as a unique identifier of a broadcaststream through which the corresponding FIC segment is being transmitted.

A second region of the FIC segment payload corresponds to an ensembleloop region, which includes an ensemble_id field, an SI_version field,and a num_channel field. More specifically, the ensemble_id field is an8-bit field indicating identifiers of an MH ensemble through which MHservices are transmitted. The MH services will be described in moredetail in a later process. Herein, the ensemble_id field binds the MHservices and the MH ensemble. The SI_version field is a 4-bit fieldindicating version information of SI data included in the correspondingensemble, which is being transmitted within the RS frame. Finally, thenum_channel field is an 8-bit field indicating the number of virtualchannel being transmitted via the corresponding ensemble.

A third region of the FIC segment payload a channel loop region, whichincludes a channel_type field, a channel_activity field, a CA_indicatorfield, a stand_alone_service_indicator field, a major_channel_num field,and a minor_channel_num field. The channel_type field is a 5-bit fieldindicating a service type of the corresponding virtual channel. Forexample, the channel_type field may indicates an audio/video channel, anaudio/video and data channel, an audio-only channel, a data-onlychannel, a file download channel, an ESG delivery channel, anotification channel, and so on. The channel_activity field is a 2-bitfield indicating activity information of the corresponding virtualchannel. More specifically, the channel_activity field may indicatewhether the current virtual channel is providing the current service.

The CA_indicator field is a 1-bit field indicating whether or not aconditional access (CA) is applied to the current virtual channel. Thestand_alone_service_indicator field is also a 1-bit field, whichindicates whether the service of the corresponding virtual channelcorresponds to a stand alone service. The major_channel_num field is an8-bit field indicating a major channel number of the correspondingvirtual channel. Finally, the minor_channel_num field is also an 8-bitfield indicating a minor channel number of the corresponding virtualchannel.

Service Table Map

FIG. 17 illustrates an exemplary bit stream syntax structure of aservice map table (hereinafter referred to as “SMT”) according to thepresent invention. According to the embodiment of the present invention,the SMT is configured in an MPEG-2 private section format. However, thiswill not limit the scope and spirit of the present invention. The SMTaccording to the embodiment of the present invention includesdescription information for each virtual channel within a single MHensemble. And, additional information may further be included in eachdescriptor area. Herein, the SMT according to the embodiment of thepresent invention includes at least one field and is transmitted fromthe transmitting system to the receiving system.

As described in FIG. 3, the SMT section may be transmitted by beingincluded in the MH TP within the RS frame. In this case, each of the RSframe decoders 170 and 180, shown in FIG. 1, decodes the inputted RSframe, respectively. Then, each of the decoded RS frames is outputted tothe respective RS frame handler 211 and 212. Thereafter, each RS framehandler 211 and 212 identifies the inputted RS frame by row units, so asto create an MH TP, thereby outputting the created MH TP to the MH TPhandler 213. When it is determined that the corresponding MH TP includesan SMT section based upon the header in each of the inputted MH TP, theMH TP handler 213 parses the corresponding SMT section, so as to outputthe SI data within the parsed SMT section to the physical adaptationcontrol signal handler 216. However, this is limited to when the SMT isnot encapsulated to IP datagrams.

Meanwhile, when the SMT is not encapsulated to IP datagrams, and when itis determined that the corresponding MH TP includes an SMT section basedupon the header in each of the inputted MH TP, the MH TP handler 213outputs the SMT section to the IP network stack 220. Accordingly, the IPnetwork stack 220 performs IP and UDP processes on the inputted SMTsection and, then, outputs the processed SMT section to the SI handler240. The SI handler 240 parses the inputted SMT section and controls thesystem so that the parsed SI data can be stored in the storage unit 290.The following corresponds to example of the fields that may betransmitted through the SMT.

The table_id field corresponds to an 8-bit unsigned integer number,which indicates the type of table section. The table_id field allows thecorresponding table to be defined as the service map table (SMT). Theensemble_id field is an 8-bit unsigned integer field, which correspondsto an ID value associated to the corresponding MH ensemble. Herein, theensemble_id field may be assigned with a value ranging from range ‘0x00’to ‘0x3F’. It is preferable that the value of the ensemble_id field isderived from the parade_id of the TPC data, which is carried from thebaseband processor of MH physical layer subsystem. When thecorresponding MH ensemble is transmitted through (or carried over) theprimary RS frame, a value of ‘0’ may be used for the most significantbit (MSB), and the remaining 7 bits are used as the parade_id value ofthe associated MH parade (i.e., for the least significant 7 bits).Alternatively, when the corresponding MH ensemble is transmitted through(or carried over) the secondary RS frame, a value of ‘1’ may be used forthe most significant bit (MSB).

The num_channels field is an 8-bit field, which specifies the number ofvirtual channels in the corresponding SMT section. Meanwhile, the SMTaccording to the embodiment of the present invention providesinformation on a plurality of virtual channels using the ‘for’ loopstatement. The major_channel_num field corresponds to an 8-bit field,which represents the major channel number associated with thecorresponding virtual channel. Herein, the major_channel_num field maybe assigned with a value ranging from ‘0x00’ to ‘0xFF’. Theminor_channel_num field corresponds to an 8-bit field, which representsthe minor channel number associated with the corresponding virtualchannel. Herein, the minor_channel_num field may be assigned with avalue ranging from ‘0x00’ to ‘0xFF’.

The short_channel_name field indicates the short name of the virtualchannel. The service_id field is a 16-bit unsigned integer number (orvalue), which identifies the virtual channel service. The service_typefield is a 6-bit enumerated type field, which designates the type ofservice carried in the corresponding virtual channel as defined in Table2 below.

TABLE 2 0x00 [Reserved] 0x01 MH_digital_television field: the virtualchannel carries television programming (audio, video and optionalassociated data) conforming to ATSC standards. 0x02 MH_audio field: thevirtual channel carries audio programming (audio service and optionalassociated data) conforming to ATSC standards. 0x03 MH_data_only_servicefield: the virtual channel carries a data service conforming to ATSCstandards, but no video or audio component. 0x04 to [Reserved for futureATSC usage] 0xFF

The virtual_channel_activity field is a 2-bit enumerated fieldidentifying the activity status of the corresponding virtual channel.When the most significant bit (MSB) of the virtual_channel_activityfield is ‘1’, the virtual channel is active, and when the mostsignificant bit (MSB) of the virtual_channel_activity field is ‘0’, thevirtual channel is inactive. Also, when the least significant bit (LSB)of the virtual_channel_activity field is ‘1’, the virtual channel ishidden (when set to 1), and when the least significant bit (LSB) of thevirtual_channel_activity field is ‘0’, the virtual channel is nothidden. The num_components field is a 5-bit field, which specifies thenumber of IP stream components in the corresponding virtual channel. TheIP_version_flag field corresponds to a 1-bit indicator. Morespecifically, when the value of the IP_version_flag field is set to ‘1’,this indicates that a source_IP_address field, avirtual_channel_target_IP_address field, and acomponent_target_IP_address field are IPv6 addresses. Alternatively,when the value of the IP_version_flag field is set to ‘0’, thisindicates that the source_IP_address field, thevirtual_channel_target_IP_address field, and thecomponent_target_IP_address field are IPv4.

The source_IP_address_flag field is a 1-bit Boolean flag, whichindicates, when set, that a source IP address of the correspondingvirtual channel exist for a specific multicast source. Thevirtual_channel_target_IP_address_flag field is a 1-bit Boolean flag,which indicates, when set, that the corresponding IP stream component isdelivered through IP datagrams with target IP addresses different fromthe virtual_channel_target_IP_address. Therefore, when the flag is set,the receiving system (or receiver) uses the component_target_IP_addressas the target_IP_address in order to access the corresponding IP streamcomponent. Accordingly, the receiving system (or receiver) may ignorethe virtual_channel_target_IP_address field included in the num_channelsloop.

The source_IP_address field corresponds to a 32-bit or 128-bit field.Herein, the source_IP_address field will be significant (or present),when the value of the source_IP_address_flag field is set to ‘1’.However, when the value of the source_IP_address_flag field is set to‘0’, the source_IP_address field will become insignificant (or absent).More specifically, when the source_IP_address_flag field value is set to‘1’, and when the IP_version_flag field value is set to ‘0’, thesource_IP_address field indicates a 32-bit IPv4 address, which shows thesource of the corresponding virtual channel. Alternatively, when theIP_version_flag field value is set to ‘1’, the source_IP_address fieldindicates a 128-bit IPv6 address, which shows the source of thecorresponding virtual channel.

The virtual_channel_target_IP_address field also corresponds to a 32-bitor 128-bit field. Herein, the virtual_channel_target_IP_address fieldwill be significant (or present), when the value of thevirtual_channel_target_IP_address_flag field is set to ‘1’. However,when the value of the virtual_channel_target_IP_address_flag field isset to ‘0’, the virtual_channel_target_IP_address_field will becomeinsignificant (or absent). More specifically, when thevirtual_channel_target_IP_address_flag field value is set to ‘1’, andwhen the IP_version_flag field value is set to ‘0’, thevirtual_channel_target_IP_address field indicates a 32-bit target IPv4address associated to the corresponding virtual channel. Alternatively,when the virtual_channel_target_IP_address_flag field value is set to‘1’, and when the IP_version_flag field value is set to ‘1’, thevirtual_channel_target_IP_address field indicates a 64-bit target IPv6address associated to the corresponding virtual channel. If thevirtual_channel_target_IP_address field is insignificant (or absent),the component_target_IP_address field within the num_channels loopshould become significant (or present). And, in order to enable thereceiving system to access the IP stream component, thecomponent_target_IP_address field should be used.

Meanwhile, the SMT according to the embodiment of the present inventionuses a ‘for’ loop statement in order to provide information on aplurality of components. Herein, the RTP_payload_type field, which isassigned with 7 bits, identifies the encoding format of the componentbased upon Table 3 shown below. When the IP stream component is notencapsulated to RTP, the RTP_payload_type field shall be ignored (ordeprecated). Table 3 below shows an example of an RTP payload type.

TABLE 3 RTP_payload_type Meaning 35 AVC video 36 MH audio 37 to 72[Reserved for future ATSC use]

The component_target_IP_address_flag field is a 1-bit Boolean flag,which indicates, when set, that the corresponding IP stream component isdelivered through IP datagrams with target IP addresses different fromthe virtual_channel_target_IP_address. Furthermore, when thecomponent_target_IP_address_flag is set, the receiving system (orreceiver) uses the component_target_IP_address field as the target IPaddress for accessing the corresponding IP stream component.Accordingly, the receiving system (or receiver) will ignore thevirtual_channel_target_IP_address field included in the num_channelsloop. The component_target_IP_address field corresponds to a 32-bit or128-bit field. Herein, when the value of the IP_version_flag field isset to ‘0’, the component_target_IP_address field indicates a 32-bittarget IPv4 address associated to the corresponding IP stream component.And, when the value of the IP_version_flag field is set to ‘1’, thecomponent_target_IP_address field indicates a 128-bit target IPv6address associated to the corresponding IP stream component.

The port_num_count field is a 6-bit field, which indicates the number ofUDP ports associated with the corresponding IP stream component. Atarget UDP port number value starts from the target_UDP_port_num fieldvalue and increases (or is incremented) by 1. For the RTP stream, thetarget UDP port number should start from the target_UDP_port_num fieldvalue and shall increase (or be incremented) by 2. This is toincorporate RTCP streams associated with the RTP streams.

The target_UDP_port_num field is a 16-bit unsigned integer field, whichrepresents the target UDP port number for the corresponding IP streamcomponent. When used for RTP streams, the value of thetarget_UDP_port_num field shall correspond to an even number. And, thenext higher value shall represent the target UDP port number of theassociated RTCP stream. The component_level_descriptor( ) representszero or more descriptors providing additional information on thecorresponding IP stream component. The virtual_channel_level_descriptor() represents zero or more descriptors providing additional informationfor the corresponding virtual channel. The ensemble_level_descriptor( )represents zero or more descriptors providing additional information forthe MH ensemble, which is described by the corresponding SMT.

FIG. 18 illustrates an exemplary bit stream syntax structure of an MHaudio descriptor according to the present invention. When at least oneaudio service is present as a component of the current event, theMH_audio_descriptor( ) shall be used as a component_level_descriptor ofthe SMT. The MH_audio_descriptor( ) may be capable of informing thesystem of the audio language type and stereo mode status. If there is noaudio service associated with the current event, then it is preferablethat the MH_audio_descriptor( ) is considered to be insignificant (orabsent) for the current event. Each field shown in the bit stream syntaxof FIG. 18 will now be described in detail.

The descriptor_tag field is an 8-bit unsigned integer having a TBDvalue, which indicates that the corresponding descriptor is theMH_audio_descriptor( ). The descriptor_length field is also an 8-bitunsigned integer, which indicates the length (in bytes) of the portionimmediately following the descriptor_length field up to the end of theMH_audio_descriptor( ). The channel_configuration field corresponds toan 8-bit field indicating the number and configuration of audiochannels. The values ranging from ‘1’ to ‘6’ respectively indicate thenumber and configuration of audio channels as given for “Default bitstream index number” in Table 42 of ISO/IEC 13818-7:2006. All othervalues indicate that the number and configuration of audio channels areundefined.

The sample_rate_code field is a 3-bit field, which indicates the samplerate of the encoded audio data. Herein, the indication may correspond toone specific sample rate, or may correspond to a set of values thatinclude the sample rate of the encoded audio data as defined in TableA3.3 of ATSC A/52B. The bit_rate_code field corresponds to a 6-bitfield. Herein, among the 6 bits, the lower 5 bits indicate a nominal bitrate. More specifically, when the most significant bit (MSB) is ‘0’, thecorresponding bit rate is exact. On the other hand, when the mostsignificant bit (MSB) is ‘0’, the bit rate corresponds to an upper limitas defined in Table A3.4 of ATSC A/53B. The ISO_639_language_code fieldis a 24-bit (i.e., 3-byte) field indicating the language used for theaudio stream component, in conformance with ISO 639.2/B [x]. When aspecific language is not present in the corresponding audio streamcomponent, the value of each byte will be set to ‘0x00’.

FIG. 19 illustrates an exemplary bit stream syntax structure of an MHRTP payload type descriptor according to the present invention. TheMH_RTP_payload_type_descriptor( ) specifies the RTP payload type. Yet,the MH_RTP_payload_type_descriptor( ) exists only when the dynamic valueof the RTP_payload_type field within the num_components loop of the SMTis in the range of ‘96’ to ‘127’. The MH_RTP_payload_type_descriptor( )is used as a component_level_descriptor of the SMT. TheMH_RTP_payload_type_descriptor translates (or matches) a dynamicRTP_payload_type field value into (or with) a MIME type. Accordingly,the receiving system (or receiver) may collect (or gather) the encodingformat of the IP stream component, which is encapsulated in RTP. Thefields included in the MH_RTP_payload_type_descriptor( ) will now bedescribed in detail.

The descriptor_tag field corresponds to an 8-bit unsigned integer havingthe value TBD, which identifies the current descriptor as theMH_RTP_payload_type_descriptor( ). The descriptor_length field alsocorresponds to an 8-bit unsigned integer, which indicates the length (inbytes) of the portion immediately following the descriptor_length fieldup to the end of the MH_RTP_payload_type_descriptor( ). TheRTP_payload_type field corresponds to a 7-bit field, which identifiesthe encoding format of the IP stream component. Herein, the dynamicvalue of the RTP_payload_type field is in the range of ‘96’ to ‘127’.The MIME_type_length field specifies the length (in bytes) of theMIME_type field. The MIME_type field indicates the MIME typecorresponding to the encoding format of the IP stream component, whichis described by the MH_RTP_payload_type_descriptor( ).

FIG. 20 illustrates an exemplary bit stream syntax structure of an MHcurrent event descriptor according to the present invention. TheMH_current_event_descriptor( ) shall be used as thevirtual_channel_level_descriptor( ) within the SMT. Herein, theMH_current_event_descriptor( ) provides basic information on the currentevent (e.g., the start time, duration, and title of the current event,etc.), which is transmitted via the respective virtual channel. Thefields included in the MH_current_event_descriptor( ) will now bedescribed in detail.

The descriptor_tag field corresponds to an 8-bit unsigned integer havinga value that identifies the current descriptor as theMH_current_event_descriptor( ). The descriptor_length field alsocorresponds to an 8-bit unsigned integer, which indicates the length (inbytes) of the portion immediately following the descriptor_length fieldup to the end of the MH_current_event_descriptor( ). Thecurrent_event_start_time field corresponds to a 32-bit unsigned integerquantity. The current_event_start_time field represents the start timeof the current event and, more specifically, as the number of GPSseconds since 00:00:00 UTC, Jan. 6, 1980. The current_event_durationfield corresponds to a 24-bit field. Herein, the current_event_durationfield indicates the duration of the current event in hours, minutes, andseconds (wherein the format is in 6 digits, 4-bit BCD=24 bits). Thetitle_length field specifies the length (in bytes) of the title_textfield. Herein, the value ‘0’ indicates that there are no titles existingfor the corresponding event. The title_text field indicates the title ofthe corresponding event in event title in the format of a multiplestring structure as defined in ATSC A/65C [x].

FIG. 21 illustrates an exemplary bit stream syntax structure of an MHnext event descriptor according to the present invention. The optionalMH_next_event_descriptor( ) shall be used as thevirtual_channel_level_descriptor( ) within the SMT. Herein, theMH_next_event_descriptor( ) provides basic information on the next event(e.g., the start time, duration, and title of the next event, etc.),which is transmitted via the respective virtual channel. The fieldsincluded in the MH_next_event_descriptor( ) will now be described indetail.

The descriptor_tag field corresponds to an 8-bit unsigned integer havingthe value TBD, which identifies the current descriptor as theMH_next_event_descriptor( ). The descriptor_length field alsocorresponds to an 8-bit unsigned integer, which indicates the length (inbytes) of the portion immediately following the descriptor_length fieldup to the end of the MH_next_event_descriptor( ). Thenext_event_start_time field corresponds to a 32-bit unsigned integerquantity. The next_event_start_time field represents the start time ofthe next event and, more specifically, as the number of GPS secondssince 00:00:00 UTC, Jan. 6, 1980. The next_event_duration fieldcorresponds to a 24-bit field. Herein, the next_event_duration fieldindicates the duration of the next event in hours, minutes, and seconds(wherein the format is in 6 digits, 4-bit BCD=24 bits). The title_lengthfield specifies the length (in bytes) of the title_text field. Herein,the value ‘0’ indicates that there are no titles existing for thecorresponding event. The title_text field indicates the title of thecorresponding event in event title in the format of a multiple stringstructure as defined in ATSC A/65C [x].

FIG. 22 illustrates an exemplary bit stream syntax structure of an MHsystem time descriptor according to the present invention. TheMH_system_time_descriptor( ) shall be used as theensemble_level_descriptor( ) within the SMT. Herein, theMH_system_time_descriptor( ) provides information on current time anddate. The MH_system_time_descriptor( ) also provides information on thetime zone in which the transmitting system (or transmitter) transmittingthe corresponding broadcast stream is located, while taking intoconsideration the mobile/portable characteristics of the MH servicedata. The fields included in the MH_system_time_descriptor( ) will nowbe described in detail.

The descriptor_tag field corresponds to an 8-bit unsigned integer havingthe value TBD, which identifies the current descriptor as theMH_system_time_descriptor( ). The descriptor_length field alsocorresponds to an 8-bit unsigned integer, which indicates the length (inbytes) of the portion immediately following the descriptor_length fieldup to the end of the MH_system_time_descriptor( ). The system_time fieldcorresponds to a 32-bit unsigned integer quantity. The system_time fieldrepresents the current system time and, more specifically, as the numberof GPS seconds since 00:00:00 UTC, Jan. 6, 1980. The GPS_UTC_offsetfield corresponds to an 8-bit unsigned integer, which defines thecurrent offset in whole seconds between GPS and UTC time standards. Inorder to convert GPS time to UTC time, the GPS_UTC_offset is subtractedfrom GPS time. Whenever the International Bureau of Weights and Measuresdecides that the current offset is too far in error, an additional leapsecond may be added (or subtracted). Accordingly, the GPS_UTC_offsetfield value will reflect the change.

The time_zone_offset_polarity field is a 1-bit field, which indicateswhether the time of the time zone, in which the broadcast station islocated, exceeds (or leads or is faster) or falls behind (or lags or isslower) than the UTC time. When the value of thetime_zone_offset_polarity field is equal to ‘0’, this indicates that thetime on the current time zone exceeds the UTC time. Therefore, thetime_zone_offset_polarity field value is added to the UTC time value.Conversely, when the value of the time_zone_offset_polarity field isequal to ‘1’, this indicates that the time on the current time zonefalls behind the UTC time. Therefore, the time_zone_offset_polarityfield value is subtracted from the UTC time value.

The time_zone_offset field is a 31-bit unsigned integer quantity. Morespecifically, the time_zone_offset field represents, in GPS seconds, thetime offset of the time zone in which the broadcast station is located,when compared to the UTC time. The daylight_savings field corresponds toa 16-bit field providing information on the Summer Time (i.e., theDaylight Savings Time). The time_zone field corresponds to a (5x8)-bitfield indicating the time zone, in which the transmitting system (ortransmitter) transmitting the corresponding broadcast stream is located.

FIG. 23 illustrates segmentation and encapsulation processes of aservice map table (SMT) according to the present invention. According tothe present invention, the SMT is encapsulated to UDP, while including atarget IP address and a target UDP port number within the IP datagram.More specifically, the SMT is first segmented into a predeterminednumber of sections, then encapsulated to a UDP header, and finallyencapsulated to an IP header. In addition, the SMT section providessignaling information on all virtual channel included in the MH ensembleincluding the corresponding SMT section. At least one SMT sectiondescribing the MH ensemble is included in each RS frame included in thecorresponding MH ensemble. Finally, each SMT section is identified by anensemble_id included in each section. According to the embodiment of thepresent invention, by informing the receiving system of the target IPaddress and target UDP port number, the corresponding data (i.e., targetIP address and target UDP port number) may be parsed without having thereceiving system to request for other additional information.

FIG. 24 illustrates a flow chart for accessing a virtual channel usingFIC and SMT according to the present invention. More specifically, aphysical channel is tuned (S501). And, when it is determined that an MHsignal exists in the tuned physical channel (S502), the corresponding MHsignal is demodulated (S503). Additionally, FIC segments are groupedfrom the demodulated MH signal in sub-frame units (S504 and S505).According to the embodiment of the present invention, an FIC segment isinserted in a data group, so as to be transmitted. More specifically,the FIC segment corresponding to each data group described serviceinformation on the MH ensemble to which the corresponding data groupbelongs.

When the FIC segments are grouped in sub-frame units and, then,deinterleaved, all service information on the physical channel throughwhich the corresponding FIC segment is transmitted may be acquired.Therefore, after the tuning process, the receiving system may acquirechannel information on the corresponding physical channel during asub-frame period. Once the FIC segments are grouped, in S504 and S505, abroadcast stream through which the corresponding FIC segment is beingtransmitted is identified (S506). For example, the broadcast stream maybe identified by parsing the transport_stream_id field of the FIC body,which is configured by grouping the FIC segments. Furthermore, anensemble identifier, a major channel number, a minor channel number,channel type information, and so on, are extracted from the FIC body(S507). And, by using the extracted ensemble information, only the slotscorresponding to the designated ensemble are acquired by using thetime-slicing method, so as to configure an ensemble (S508).

Subsequently, the RS frame corresponding to the designated ensemble isdecoded (S509), and an IP socket is opened for SMT reception (S510).According to the example given in the embodiment of the presentinvention, the SMT is encapsulated to UDP, while including a target IPaddress and a target UDP port number within the IP datagram. Morespecifically, the SMT is first segmented into a predetermined number ofsections, then encapsulated to a UDP header, and finally encapsulated toan IP header. According to the embodiment of the present invention, byinforming the receiving system of the target IP address and target UDPport number, the receiving system parses the SMT sections and thedescriptors of each SMT section without requesting for other additionalinformation (S511).

The SMT section provides signaling information on all virtual channelincluded in the MH ensemble including the corresponding SMT section. Atleast one SMT section describing the MH ensemble is included in each RSframe included in the corresponding MH ensemble. Also, each SMT sectionis identified by an ensemble_id included in each section. Furthermoreeach SMT provides IP access information on each virtual channelsubordinate to the corresponding MH ensemble including each SMT.Finally, the SMT provides IP stream component level information requiredfor the servicing of the corresponding virtual channel. Therefore, byusing the information parsed from the SMT, the IP stream componentbelonging to the virtual channel requested for reception may be accessed(S513). Accordingly, the service associated with the correspondingvirtual channel is provided to the user (S514).

Hereinafter, transmission/reception of service data having a formatdifferent from the existing MH format in an MH system according toanother embodiment of the present invention will be described. At thistime, the service having the different format includes a MediaFLO™service for providing a mobile broadcasting service of a subscriptionbase via a single physical channel. Hereinafter, for convenience ofdescription, for example, the MediaFLO™ service will be described, butthe present invention is not limited thereto.

In order to transmit/receive data for the MediaFLO™ service in the MHsystem, the data for the MediaFLO™ service should be changed to atransmission/reception format of the MH system. In addition, forconditional access, an interface between layers on the existing MHsystem and layers for the MediaFLO™ service should be performed.

Hereinafter, a protocol stack for transmitting/receiving data for aMediaFLO™ service in an MH system under conditional access will bedescribed.

FIG. 25 is a view showing a protocol stack of an MH system according toan embodiment of the present invention.

Hereinafter, referring to FIG. 25, for transmission/reception of theMediaFLO™ service data in the MH system under the conditional access, aspecific layer for an interface between an MH transport layer and amedia adaptation layer of the MediaFLO™ will be defined and signalingdata associated with the transmission/reception will be defined. At thistime, the specific layer is called an MH encryption/decryption layer.

The embodiment of the protocol stack in the MH system shown in FIG. 25is the structure that data for the MediaFLO™ service is interfaced via async layer, a file delivery layer and an IP adaptation layer inassociation with the MediaFLO™ service and the interfaced data isinterfaced in the MH encryption/decryption layer again in associationwith the conditional access and is transmitted via an MH transport layerand an MH physical layer. The protocol stack deals with signaling, thatis, an MH signaling layer, in association with the interface in the MHsystem of the MediaFLO™ service data.

The protocol stack shown in FIG. 25 includes a media codecs layer, anon-real time files layer and an IPv4/IPv6 layer, all of which are usedto transmit the data for the MediaFLO™ service, and includes the synclayer, the file delivery layer and the IP adaptation layer, all of whichenable the data for the MediaFLO™ service downloaded from the layers tobe interfaced with the MH system.

The media codecs layer is a layer for a real-time applications service,a non-real time files layer is a layer for a file-based applicationsservice, and the IPv4/IPv6 layer is a layer for an IP datacastapplications service. At this time, the detailed description of thelayers associated with the MediaFLO™ service will refer to, for example,the TIA-1130 (media adaptation layer) and will be omitted herein, forconvenience of description. In association with the MediaFLO™ service,the non-real time files layer, the file delivery layer, the IPv4/IPv6layer and the IP adaptation layer may be defined in the existing MHformat and may be transmitted.

In the protocol stack, the FIC layer and the MH-signaling layer arelayers for signaling in the MH system. The MH transport layer and the MHphysical layer are layers for packetizing the data for the interfacedMediaFLO™ service and transmitting the packetized data.

The detailed description of the interface and the signaling associatedwith the protocol stack of the MH system will be described later.

FIG. 26 is a conceptual block diagram of an MH receiver according toanother embodiment of the present invention.

Referring to FIG. 26, the MH receiver according to another embodiment ofthe present invention includes an encrypt/decrypt handler 2618, anRS-frame handler 2620, a physical parameter handler 2621, an FIC handler2622, a non-IP MH-signaling decoder 2625, an IP-based MH-signalingdecoder 2626, a sync layer handler 2632, a file delivery layer handler2633, an IP adaptation layer handler 2634, an MH-signaling database2627, a channel manager 2629, and a service manager 2630.

Hereinafter, a process of receiving and processing data for a MediaFLO™service transmitted according to the protocol stack shown in FIG. 25 inthe MH system and the configuration thereof will be mainly described.The same portions as the configuration of the MH receiver according tothe embodiment of the present invention shown in FIG. 1 will cite theabove description. In particular, control data necessary for performingencryption/decryption associated with the function of theencrypt/decrypt handler will be described in association with theconditional access. A dotted line of FIG. 26 denotes the flow of controldata and a solid line denotes the flow of actual data. Thebelow-described layers indicate the layers of the protocol stack of FIG.25.

The RS-frame handler 2620 processes an RS-frame which is output from theMH physical layer. The signaling information associated with theMediaFLO™ service in the processed RS-frame is transmitted to the non-IPMH signaling buffer 2623 and a flow packet associated with the MediaFLO™service is transmitted to the flow packet handler 2619.

The flow packet handler 2619 receives the flow packet from the RS-framehandler 2620, extracts type information in the header of the receivedflow packet, and selects a handler associated with the flow packet fromthe sync layer handler 2632, the file delivery layer handler 2633 andthe IP adaptation layer handler 2634 according to the extracted typeinformation. The flow packet handler 2619 transmits the received flowpacket so as to be processed by the selected handler.

The encrypt/decrypt handler 2618 receives an encrypted stream from theflow packet handler 2619, receives control data to decryption from thenon-IP MH-signaling decoder 2625, decrypts the encrypted stream,transmits the decrypted stream to the layer handlers, that is, the synclayer handler 2632, the file delivery layer handler 2633 and the IPadaptation layer handler 2634.

The physical parameter handler 2621 processes a physical layer parameterrequired by a management layer or higher layer.

The FIC handler 2622 processes FIC data. At this time, in order toprocess the FIC data, parameters of the physical layer are necessary.The parameters of the physical layer are obtained from TPC data, whichis decoded and transmitted by the signaling decoder 2616, by thephysical parameter handler 2621.

The non-IP MH-signaling decoder 2625 receives and processes MH-signalinginformation transmitted via the FIC handler 2622 and non-IP MH-signalinginformation transmitted by the RS-frame.

The IP-based MH-signaling decoder 2626 processes the MH-signalinginformation transmitted via the FIC handler 2622 and IP-basedMH-signaling information transmitted by the RS-frame.

The sync layer handler 2632 receives and processes the flow packet inwhich the conditional access of data, to which the conditional access isapplied in the MH encryption/decryption layer, is released by theencrypt/decrypt handler 2618 via the sync layer, among the flow packetsconfiguring the RS-frame.

The file delivery layer handler 2633 receives and processes the flowpacket in which the conditional access of data, to which the conditionalaccess is applied in the MH encryption/decryption layer, is released bythe encrypt/decrypt handler 2618 via the file delivery layer, among theflow packets configuring the RS-frame.

The IP adaptation layer handler 2634 receives and processes the flowpacket in which the conditional access of data, to which the conditionalaccess is applied in the MH encryption/decryption layer, is released bythe encrypt/decrypt handler 2618 via the IP adaptation layer, among theflow packets configuring the RS-frame.

The MH-signaling database 2627 serves to store the signaling datareceived in the non-IP or IP format.

The channel manager 2629 manages a user input such as channel setting bythe MH user interface.

The service manager 2630 manages the user input such as service settingusing an EPG display and an MPG by the MH user interface.

The MH receiver of FIG. 26 requires a variety of supplementaryinformation such as authentication of a device and a user, a receptionright level of the user, and a control word (key) used for performingencryption/decryption. The supplementary information necessary forperforming the conditional access is also called control data. In orderto acquire the control data, for example, an entitlement managementmessage (EMM), an entitlement control message (ECM) and other datanecessary for the conditional access may be required. The control datamay be, for example, transmitted in a state of being included in aservice map table or an electronic service guide (ESG), but the presentinvention is not limited thereto. That is, the control data may betransmitted by other methods. The MH receiver according to anotherembodiment of the present invention can receive the EMM, the ECM and theother data and obtain information required for the configuration of thecontrol data from the transmitted data.

In FIG. 26, the MH receiver may store the received control data in, forexample, the MH-signaling database 2627. Alternatively, the control datamay be stored in a separate storage space or may be received, extractedand used in real time according to the characteristics of the controldata. For example, if the MediaFLO™ service to which the conditionalaccess is applied is used according to the request of the user, the MHreceiver stores the control data associated with the service in theMH-signaling database 2627 or a separate stable storage space andextracts the data or extracts the data in real time, and transmits thedata to the encrypt/decrypt handler 2618. The encrypt/decrypt handler2618 releases the conditional access of the service using the extractedcontrol data so as to enable the MediaFLO™ service data to be processedby the layer handlers 2632 to 2634.

Next, the structure of the RS frame and packet multiplexing according toanother embodiment of the present invention will be described. FIG. 27is a view showing the structure of an RS frame including a multiplexedpacket according to another embodiment of the present invention.

FIG. 27 shows, for example, the format of the RS frame for transmittingdata corresponding to an MH ensemble per MH frame as the output of an MHphysical layer subsystem.

One RS frame may transmit a plurality of MH services. Data configuringone MH service may be continuously transmitted in the RS frame in astate of forming one zone. One MH service may be configured by aplurality of flow packets.

The RS frame is configured in the form of a two-dimensional byte arrayof 187xN bytes. Accordingly, in the MH transport layer, each row of theRS frame configures the MH transport packet (MH TP).

FIG. 28 is a view showing the structure of an MH TP according to anembodiment of the present invention.

Referring to FIG. 28, one MH TP is configured by an MH transport packetheader (MH TP header) (2 bytes) and an MH transport packet payload (MHTP payload) (N-2 bytes).

The MH TP header includes, for example, a type indicator field, an errorindicator field, a stuff indicator field and a pointer field.Hereinafter, the fields will be described.

First, the type indicator field (3 bits) indicates the type of the datacarried in a payload portion of the MH TP. At this time, the field valueand the meaning thereof may be defined as shown in Table 4.

TABLE 4 Type Indicator Meaning 000 MH Signaling Data 001 IP Datagram 010Sync Layer Data 011 File Delivery Layer Data 100 IP Adaptation LayerData 101-111 Reserved

Referring to Table 4, the type of the data carried in the payload of theMH TP is MH signaling data if the value of the type indicator field is“000”, the type of the data carried in the payload of the MH TP is IPdatagram if the value of the type indicator field is “001”, the type ofthe data carried in the payload of the MH TP is sync layer data if thevalue of the type indicator field is “010”, the type of the data carriedin the payload of the MH TP is file delivery layer data if the value ofthe type indicator field is “011”, and the type of the data carried inthe payload of the MH TP is IP adaptation layer data if the value of thetype indicator field is “100”. The values of the type indicator field of“101” to “111” are reserved for future use.

The type of the service transmitted/received in the MH system may beidentified by the value of the type indicator field. For example, if thevalue of the type indicator field is “010” to “100”, the receiver canknow that the data for the MediaFLO™ service is transmitted via the MHTP, from the value of the field. If the value of the field is “000”which indicates the MH signaling data, or “001” which indicates the IPdatagram, the data is included in the MH TP having the existing MHformat and the detailed description thereof will cite the abovedescription.

The error indicator field (1 bit) is an indicator indicating whether ornot an error is included in the MH TP. At this time, it is indicatedthat the error is not found if the value of the error indicator field is“0” and it is indicated that the error is found if the value of theerror indicator field is “1”, thereby indicating theexistence/nonexistence of the error.

The stuff indicator field (1 bit) is an indicator indicating whether ornot stuffing bytes are included in the MH TP. At this time, it isindicated that the stuffing bytes do not exist if the value of the stuffindicator field is “0” and it is indicated that a start portion of thepacket payload is the stuffing field if the value of the stuff indicatorfield is “1”, thereby indicating the existence/nonexistence of thestuffing field. The stuffing bytes indicate the stuffing bytes (K bytes)which are included in one MH TP, if necessary, and the stuffing fieldincluding the K bytes may be the start portion of the packet payload. Ifthe length of the stuffing field is 1 byte, the value of a first byte ofthe stuffing field may be set to “0xFF”. If the length of the stuffingfield is 2 bytes, the value of the first byte of the stuffing field isset to “0xFE” and the value of the second byte of the stuffing field isset to “0xFF”. If the length of the stuffing field is 2 bytes or more,the value of first two bytes of the field may indicate the number ofbytes in the stuffing byte field.

The pointer field (11 bits) indicates the start point of a new packet inthe payload of the MH TP. The start point of the new packet mayindicate, for example, the start point of the flow packet header.

The values of the fields in the MH TP header are exemplary forconvenience of description and the present invention is not limitedthereto.

Next, one MH TP includes a stuffing portion (K bytes) and a payloadportion (N-2-K bytes) in addition to the MH TP header. At this time, thestuffing portion and the payload portion may be collectively called apayload.

For example, referring to the protocol stack of FIG. 25, if the flowpacket to which the conditional access is applied is included in theflow packets of the sync layer, the file delivery layer and the IPadaptation layer associated with the MediaFLO™ service, additionalcontrol data for controlling the flow packet to which the conditionalaccess is applied is transmitted together. As the control data, the ECMincluding the control word (key) necessary for performing the decryptionof the encrypted flow packet and the control data necessary for theother conditional access are transmitted.

The structure of the RS frame in which a plurality of packets for theMediaFLO™ service shown in FIG. 27 is multiplexed will be described. Inthe RS frame, data packets A to P are multiplexed.

In the structure of the RS frame, the type of the data packet includedin the RS frame payload portion of each row is described in a leftcolumn called the RS frame header. For example, in the RS frame shown inFIG. 27, the RS frame header portion of a first row is represented by A,which indicates that the signaling data packet header is included in thepayload portion of the first row. If any one of B to D is represented inthe RS frame header of a specific row of the RS frame in the samemanner, it is indicated that the data packet indicated by any one of Bto D is included in the RS frame payload of the specific row.

FIG. 27 shows an example of multiplexing data for four services 1 to 4.That is, Service 1 is a service including a sync layer packet, Service 2is a service including a file delivery layer packet, Service 3 is aservice including an IP adaptation layer packet, and Service 4 is aservice in which the above-described packets are multiplexed. It can beseen that the service packets are transmitted via different flowpackets.

Next, a process of encrypting, packetizing and transmitting dataassociated with a sync layer in association with the MediaFLO™ servicewill be described. FIG. 29 is a view showing a process of packetizingsync layer packets according to an embodiment of the present invention.FIG. 30 is a view showing the format of a flow packet according to anembodiment of the present invention.

The sync layer functions as an interface between a media codecs layerand an MH transport layer, for transmission of data for real-timeapplications in an MH system as described above. At this time, thereal-time applications include, for example, a video, an audio, and atimed text.

FIG. 29 shows a process of packetizing media frames downloaded from themedia codec layer in the sync layer so as to configure sync layerpackets and packetizing the configured sync layer packets to MHtransport packets (TPs) in an MH transport layer via theencryption/decryption layer, for the conditional access function.

In the sync layer, the media frames having variable lengths aredownloaded from the media codec layer. The sync headers are prefixed tothe downloaded media frames so as to configure the sync layer packets.At this time, a packet configured by prefixing a header to a sync layeradaptation frame (SLAF) may be inserted between the sync layer packets.

The sync header may include a media type (MT), a media common header(MCH), a media specific header (MSH) and a sync layer adaptation type(SLAT). For example, in FIG. 29, each of the headers prefixed in theprocess of packetizing the media frames includes the MT, the MCH and theMSH. The header for packetizing the SLAF includes the MT indicating themedia type and the SLAT.

In the MH encryption/decryption layer, the sync layer packets downloadedfrom the sync layer are encrypted. In the MH encryption/decryptionlayer, the values of the lengths of the sync layer packets encrypted inthe encryption process are inserted. Since the decryption cannot beperformed when the receiver does not know the lengths of the encryptedsync layer packets encrypted in the MH encryption/decryption layer, thevalues of the lengths are necessary for decryption. In FIG. 29, zones towhich the encryption is applied are considered as sync layer packetzones denoted by a dotted line in the MH encryption/decryption layer.

In the MH transport layer, the encrypted sync layer packets aredownloaded from the MH encryption/decryption layer and are packetized tothe MH TP which can be transmitted via the MH system.

The packetized MH TP may be configured by prefixing a flow packet headerto the encrypted sync layer packets and the flow packet payloadincluding the length values of the sync layer packets so as to a flowpacket and prefixing an MH TP header to the configured flow packet.

The MH TP header may have 2 bytes and the flow packet corresponding tothe remaining MH transport packet payload may have (N-2) bytes.Referring to FIG. 30, the flow packet is divided into a 5-byte flowpacket header and an N-2-5-byte flow packet payload.

Referring to FIG. 29, one MH TP (N bytes) may include one flow packet(N-2 byte) and one flow packet (N-2 bytes) may include the encryptedsync layer packets and the flow packet payload (N-2-5 bytes) includingthe length value except for the flow packet header (5 bytes).

Referring to FIG. 30, the flow packet header (5 bytes) includes a FlowID field (20 bits) for identifying the flow packet, a CHECKSUM_ACTIVEfield (1 bit) indicating whether or not cyclic redundancy check (CRC) isapplied to the flow packet, an NUM_SYNC_PKTS field (1 bit) indicatingthe number of sync layer packets transmitted via the flow packetpayload, an FD_FLOW_TYPE field (1 bit) indicating the type of the flowpacket, an FASB_ALLOWED field (1 bit) indicating whether or not the flowpacket is transmitted over at least one RS frame, and aSTREAM_ENCRYPTION_ACTIVE field (16 bits) indicating whether or notencryption is applied to the flow packet payload. If the flow packet isa real-time application flow packet, the value of the FASB_ALLOWED fieldmay be set to “FALSE”.

In the present invention, if the encryption for conditional access isapplied to the sync layer packets included in the flow packet payload,among the fields configuring the flow packet header shown in FIG. 30,the STREAM_ENCRYPTION_ACTIVE field may be set to “1”. Here, “1” isarbitrarily set by the applicant, for indicating whether or notencryption is applied, and other expressions indicating whether or notencryption is applied may be used.

However, if the encryption for conditional access is not applied to thesync layer packets included in the flow packet payload, the sync layerpackets bypass the MH encryption/decryption layer, are packetized to theMH TPs in the MH transport layer and are transmitted to the physicallayer. In this case, the sync layer functions as the interface for theMediaFLO™ service. The value of the STREAM_ENCRYPTION_ACTIVE in the flowpacket header is set to a value different from that of the case wherethe encryption for the conditional access is applied, for example, “0”,thereby indicating whether or not the encryption is applied to the synclayer packets. This becomes important information which can determinewhether or not the decryption of the data in the MH TPs received by thereceiver is performed. The formats of the multiplexed MH TPs may beequal regardless of whether or not the encryption is applied.

Accordingly, the RS frame handler 2620 of the receiver shown in FIG. 26searches for the MH TP header having the above-described configuration,parses the MH TPs of which the type indicator of the header is “010”,sends the packets to the flow packet handler 2619. The flow packethandler 2619 extracts and sends the sync layer packets to the sync layerhandler 2632. If the packet to which the encryption is applied isincluded in the packets delivered to the flow packet handler 2619 viathe RS frame handler 2620, the packet is decrypted by theencrypt/decrypt handler 2618 and the decrypted packet is delivered tothe sync layer handler 2632.

Subsequent to the process of packetizing the sync layer packets, aprocess of packetizing file delivery layer packets will be described.FIGS. 31A and 31B are views showing the configuration of a file deliveryprotocol (FDP) packet and a file delivery control protocol (FDCP) packetpacketized in an MH transport layer according to an embodiment of thepresent invention. FIG. 32 is a view showing the header of an MHtransport packet associated with FIGS. 31A and 31B.

The file delivery layer functions as an interface between an MHtransport layer and a non-real time files layer, for transmission ofdata for non-real time applications.

The file delivery layer may deliver the FDP packet and the FDCP packetfor file delivery control to the MH transport layer as different flowpackets. At this time, the FDP and the FDCP packets are packetized tothe MH TPs via the MH encryption/decryption layer and the configurationsthereof are shown in FIG. 31A (FDP packet) and FIG. 31B (FDCP packet).In FIGS. 31A and 31B, portions denoted by a dotted line denote zones towhich the encryption is applied.

Since the process of applying the encryption to the FDP and FDCP packetsin the MH encryption/decryption layer and packetizing the FDP and theFDCP packets in the MH transport layer is similar to the processassociated with the sync layer packets of FIGS. 29 and 30, the commonportions will cite the above description and the detailed descriptionthereof will be omitted. Accordingly, referring to FIG. 32, theSTREAM_ENCRYPTION_ACTIVE field of the flow packet header is set to “1”if the encryption is applied and is set to “0” if the MHencryption/decryption layer is bypassed, similar to the sync layer. Theflow packet payload having the variable length includes the FDP packetand the length information of the FDP packet or the FDCP packet and thelength information of the FDCP packet.

Finally, subsequent to the process of packetizing the file deliverylayer packets, a process of packetizing IP adaptation layer packets willbe described. FIG. 33 is a view showing IP datagram packets encryptedand packetized in an MH transport layer according to an embodiment ofthe present invention. FIG. 34 is a view showing the header of the MH TPassociated with FIG. 33.

The IP adaptation layer functions as an interface between the IPv4/IPv6layer and the MH transport layer, for transmission of data for the IPdatacast applications.

The IP adaptation layer may deliver the IP datagrams to the MH transportlayer as different packets. The IP datagrams are packetized to the MHTPs via the MH encryption/decryption layer. FIG. 33 shows theconfiguration of the packetized IP datagrams. In FIG. 33, portionsdenoted by a dotted line denote zones to which the encryption isapplied.

The process of applying the encryption to the IP datagrams in the MHencryption/decryption layer and packetizing the IP datagrams in the MHtransport layer is similar to the process associated with the sync layerpackets, the common portions will cite the above description and thedetailed description thereof will be omitted. Referring to FIG. 34, theSTREAM_ENCRYPTION_ACTIVE field of the flow packet header is set to “1”if the encryption is applied and is set to “0” if the MHencryption/decryption layer is bypassed. The flow packet payloadincludes the IP datagram and the length information of the IP datagram.

Next, the encryption and decryption algorithm will be described indetail. FIGS. 35A and 35B are views showing an encryption algorithmaccording to an embodiment of the present invention, and FIGS. 36A to36B are views showing a decryption algorithm according to an embodimentof the present invention;

In association with the conditional access of the present invention, theencryption/decryption applied to the service channel may be performedaccording to various algorithms. In the present specification, forconvenience of description, an advanced encryption standard (AES) isdescribed and the detailed contents associated with the AES refers toFIPS-197 which will be omitted herein.

In the AES, any one of 128 bits, 192 bits or 256 bits may be used as akey size. Hereinafter, in the description of the encryption anddecryption algorithm according to the present invention, forfacilitation of implementation, it is assumed that the key size of 128bits is used and a counter (CTR) mode of the operation modes of the AESis used.

In the CTR mode, the encryption and the decryption are performed asshown in FIGS. 35A and 35B and FIGS. 36A and 36B.

The encryption according to the embodiment of the present invention willnow be described with reference to FIGS. 35A and 35B. The stream shownin an uppermost portion of FIG. 35A is, for example, sync layer packetsto which the encryption is not applied. In the lengths and the synclayer packets configuring the stream, the encryption is applied to thesync layer packets except for the lengths.

Each of the sync layer packets is divided into P1 to Pn each having 16bytes and Pn indicates a residue block. P1 to Pn are encrypted using AESencryption modules (of which the number is n) corresponding thereto.That is, the AES encryption modules receive counter values and keyvalues and output values associated with the encryption using thecounter values and the key values. The output values are exclusive-OR(XOR) with the packets P1 to Pn so as to perform the encryption C1 toCn.

Hereinafter, the decryption corresponding to the encryption according tothe embodiment of the present invention will be described with referenceto FIGS. 36A and 36B. An uppermost portion of FIG. 36A shows MH TPsincluding the decrypted sync layer packets. C1 to Cn configuring onesync layer packet shown in FIG. 36A indicate packets encrypted in theprocess of FIG. 35B.

The decryption process of the present invention is performed in a mannerinverse to the encryption process of FIG. 35A. That is, AES decryptionmodules receive counter values and key values and output valuesassociated with the decryption. The output values are exclusive-OR (XOR)with the encrypted packets C1 to Cn so as to obtain the decryptedpackets P1 to Pn. The obtained packets P1 to Pn are equal to the initialpackets P1 to Pn which are not encrypted as shown in FIG. 35A,respectively.

In order to perform the encryption and decryption processes in the CTRmode, for example, initial counter values shown in FIG. 37 of theAES-CTR mode configured according to the embodiment of the presentinvention are necessary.

Referring to FIG. 37, for example, the counter value is “0” if the keysize is 0 to 72 bits, is “Type Indicator” if the key size is 73 to 75bits, is “System Time” if the key size is 76 to 107 bits, and is “FlowID” if the key size is 108 to 127 bits. The type indicator indicates thetype of the encrypted stream. The system time defines the system time ofa super frame. The flow ID identifies the flow packet ID of theencrypted stream.

FIG. 38 is a view explaining a process of encrypting and decrypting aresidue data block according to an embodiment of the present invention.

The encrypted and decrypted packets are divided into 128-bit blocks. Ifa last data block does not have 128 bits, the AES encryption/decryptionmodule outputs are exclusive-OR (XOR) by the residue data block from anupper bit thereof so as to perform the encryption and the decryption.

Next, in association with signaling information for the process of thedata for the MediaFLO™ service, a service map table (SMT-MH) accordingto another embodiment of the present invention will be described. FIG.39 is a view showing the syntax of the bitstream of a service map tableaccording to another embodiment of the present invention.

Among the MH TPs transmitted via the RS frame shown in FIG. 27, an MH TPof which a type indicator is set to “000” is located at a foremost sideof the RS frame, and a service map table including signaling datadescribing the data structure of the RS frame is transmitted via the MHTP located at the foremost side of the RS frame.

The service map table delivers information on the flow packets belongingto the MH services transmitted via the RS frame to the receiver. Theservice map table may be processed by the non-IP MH signaling decoder2625 of the MH receiver of FIG. 26.

The service map table delivers information on the start and the end ofthe MH TPs belonging to the MH services transmitted via the RS frame soas to enable the RS frame handler 2620 to extract desired MH servicedata although the receiver does not have the IDs of the MH services.

The embodiment of the service map table of FIG. 39 is written accordingto the MPEG-2 short form, but is not mandatory and may be writtenaccording to other short forms. The same contents as the service maptable of FIG. 17 will cite the above description and the portionsassociated with the present embodiment will be mainly described.

In the channel to which the conditional access is applied, additionalinformation necessary for the conditional access and a control word(key) for description is necessary. Accordingly, a transmitter fortransmitting a service should transmit additional information indicatingfrom where the control word necessary for the decryption of the channelis transmitted and other information necessary for the conditionalaccess.

The information necessary for the conditional access may be, forexample, defined in the service map table. The information necessary forthe conditional access may be defined by a descriptor of a descriptor( )or additional_descriptor( ) zone of the service map table. Hereinafter,the descriptor including the information necessary for the conditionalaccess is called MH_CA_descriptor( ).

Referring to FIG. 39, a first_MH_TP_num field indicates a first MH TPamong several MH TPs including the flow packets and a last_MH_TP_numfield indicates a last MH TP. This distinguish the MH transport packetto which MH_CA_descriptor( ) is applied included in a correspondingsection.

Next, the MH_CA_descriptor( ) according to an embodiment of the presentinvention will be described. The syntax of the bitstream of theMH_CA_descriptor( ) will now be described. FIG. 40 is a view showing thesyntax of the bitstream of the MH_CA_descriptor( ) according to anembodiment of the present invention. At this time, the MH_CA_descriptor() is written in the MPEG-2 short form, but may be written in otherforms.

Hereinafter, the fields of the MH_CA_descriptor will be described.

A descriptor_tag field (8 bits) indicates that the descriptor is theMH_CA_descriptor( ).

A descriptor_length field (8 bits) indicates the length (in bytes)immediately following this field up to the end of this descriptor.

A CA_System_ID field identifies a conditional access system type appliedto the ECM and the other information necessary for the conditionalaccess.

An MH_CA_Flow_ID field defines the flow ID for identifying the flowpacket via which the information necessary for the ECM and theconditional access are transmitted.

In the case where a plurality of channels is included in the service,the information necessary for the conditional access associated with thechannels is defined if the MH_CA_descriptor( ) is included in thedescriptor( ) zone of the service map table section, and the informationnecessary for the conditional access of all the channels for providingthe service is defined if the additional_descriptor( ) zone is includedin the MH_CA_descriptor( ).

Next, the structure of the RS frame to which the conditional access isapplied according to another embodiment of the present invention will bedescribed. FIG. 41 is a view showing the structure of the RS frame towhich conditional access is applied, according to another embodiment ofthe present invention, and FIG. 42 is a view showing another embodimentof a service map table (SMT-MH) configured by the structure of FIG. 41.

The structure of the RS frame to which the conditional access is appliedto the packets for Service 2 among the data for Service 1 to Service 4shown in FIG. 41 will be described.

FIG. 42 shows an example of the SMT-MH of Service 2 in the structure ofthe RS frame of FIG. 41. In FIG. 42, a major channel number, a minorchannel number, a target IP address and a descriptor are shown. In thelower portion FIG. 42, it can be seen that the additional_descriptor istransmitted.

For example, if a channel 30-5 is selected by the user, the contents ofthe MH_CA_descriptor corresponding to the channel 30-5 should be checkedin FIG. 42. Accordingly, it can be seen that control data necessary forreleasing the conditional access of the channel 30-5 is transmitted bythe flow packet having a flow ID value of “0x0011 B” in the service andthe target IP address is “200.200.200.5”. The values shown in FIG. 42are only exemplary and the present invention is not limited to thevalues.

Accordingly, referring to FIGS. 39 to 42, if a specific channel is setby the user using the SMT-MH defined according to the embodiment of thepresent invention, although the conditional access is applied to theservice transmitted via the specific channel, it is determined via whichflow packet the control data necessary for releasing the conditionalaccess is transmitted, by checking the contents of the MH_CA_descriptorin the service map table section corresponding to the specific channel.Accordingly, the conditional access of the channel is released and thechannel is provided to the user.

Hereinafter, a process of extracting data transmitted via the MH TPlayer in the MH receiver in order to provide a broadcast or service towhich the conditional access is applied will be described. FIGS. 43 to45 are flowcharts illustrating a process of extracting data according toan embodiment of the present invention.

When the power of the MH receiver is turned on, the RS frame in thereceived broadcast or service is decoded (S4301).

The SMT-MH including the signaling information of the data for theMediaFLO™ service is extracted from the decoded RS frame and theMH_CA_descriptor in the extracted MT-MH is extracted (S4302).

The steps S4301 to S4302 may be, for example, performed by the RS framehandler 2620 of the MH receiver shown in FIG. 26.

If the SMT-MH including the signaling information is extracted in thestep S4302, the first_MH_TP_num field and the last_MH_TP_num field areparsed from the extracted SMT-MH section (S4303).

The step S4303 may be, for example, performed by the non-IP MH signalingdecoder 2625 of the MH receiver shown in FIG. 26.

The MH TPs are extracted from the RS frame on the basis of the extractedSMT-MH and the parsed first_MH_TP_num field and last_MH_TP_num field. Atthis time, at least one MH TP including the conditional accessinformation and the key is extracted from the extracted MH TPs inassociation with the MH TPs including the flow packet to which theconditional access is applied (S4304).

The header of the at least one MH TP including the conditional accessinformation and the key is parsed (S4305).

The steps S4304 to S4305 may be, for example, performed by the RS framehandler 2620 of the MH receiver shown in FIG. 26.

In the step S4304, the header of the MH TP is parsed and the typeindicator field is extracted. The flow packet header is parsed on thebasis of the value of the extracted type indicator (S4306). For example,the flow packet includes the sync layer packets if the value of theextracted type indicator is “010”, includes the FDP packet and the FDCPpacket if the value of the extracted type indicator is “011”, andincludes the IP datagram packets if the value of the extracted typeindicator is “100”.

Hereinafter, the flow packet of which the type indicator is “010”, thatis, the flow packet including the sync layer packets, will be describedwith reference to FIG. 43.

That is, it is determined whether the value of theSTREAM_ENCRYPTION_ACTIVE field in the flow packet header including theparsed sync layer packets is “1” or “0” (S4307).

If it is determined that the value of the STREAM_ENCRYPTION_ACTIVE fieldis “1”, the sync layer packets included in the flow packet are theencrypted packets and thus are decrypted by the above-described method(S4308).

The decryption may be, for example, performed by theencryption/decryption handler 2168 of the MH receiver shown in FIG. 26.

After the decryption is performed or if it is determined that the valueof the STREAM_ENCRYPTION_ACTIVE field is “0” in the step S4307, the synclayer packets in the flow packet are extracted (S4309).

The steps S4306 to S4309 except for S4308 may be, for example, performedby the flow packet handler 2619 of the MH receiver shown in FIG. 26.

If the encrypted sync layer packets are decrypted and extracted from theflow packet in the step S4309, a sync layer action is performed (S4310).

The sync layer action may be, for example, performed by the sync layerhandler 2632 of the MH receiver shown in FIG. 26.

By performing the above-described process, the real time applicationscan be provided to the user via the MH transport layer.

Next, the flow packet, of which the extracted type indicator is “011”and includes the FDP packet and the FDCP packet, will be described withreference to FIG. 44. The steps S4401 to S4406 of FIG. 44 are equal tothe steps S4301 to S4306 and will cite the description of FIG. 43.Hereinafter, the description will be made from the step S4306.

Instead of the sync layer packets, if the FDP packet and the FDCP packetare included in the flow packet according to the value of the extractedtype indicator, the headers of the flow packets including the FDP packetand the FDCP packet are extracted and parsed (S4406).

It is determined whether the value of the STREAM_ENCRYPTION_ACTIVE fieldin the flow packet header including the parsed FDP and the FDCP packetsis “1” or “0” (S4407).

If it is determined that the value of the STREAM_ENCRYPTION_ACTIVE fieldis “1”, the FDP and the FDCP packets included in the flow packet are theencrypted packets and thus are decrypted by the above-described method(S4408).

After the decryption is performed in the step S4408 or if it isdetermined that the value of the STREAM_ENCRYPTION_ACTIVE field is “0”in the step S4407, the FDP and the FDCP packets in the flow packet areextracted (S4409).

If the encrypted FDP and the FDCP packets are decrypted and extractedfrom the flow packet in the step S4409, a file delivery layer action isperformed (S4410).

By performing the above-described process, the file-based applicationscan be provided to the user via the MH transport layer.

Finally, the flow packet of which the extracted type indicator is “100”,that is, the flow packet including the IP datagrams, will be describedwith reference to FIG. 45. The steps S4501 to S4506 of FIG. 45 are equalto the steps S4301 to S4306 and will cite the description of FIG. 43.Hereinafter, the description will be made from the step S4507.

Instead of the sync layer packets, if the IP datagrams are included inthe flow packet according to the value of the extracted type indicator,the headers of the flow packets including the IP datagrams are extractedand parsed (S4507).

It is determined whether the value of the STREAM_ENCRYPTION_ACTIVE fieldin the flow packet header including the parsed IP datagrams is “1” or“0” (S4508).

If it is determined that the value of the STREAM_ENCRYPTION_ACTIVE fieldis “1”, the IP datagrams included in the flow packet are the encryptedpackets and thus are decrypted by the above-described method (S4509).

After the decryption is performed in the step S4509 or if it isdetermined that the value of the STREAM_ENCRYPTION_ACTIVE field is “0”in the step S4508, the IP datagrams in the flow packet are extracted(S4510).

If the encrypted IP datagrams are decrypted and extracted from the flowpacket in the step S4510, an IP adaptation layer action is performed(S4511).

By performing the above-described process, the IP datacast applicationscan be provided to the user via the MH transport layer.

The blocks configuring the MH receiver for performing the steps of FIG.45 are equal to the blocks described with reference to FIG. 43.

According to the present invention, the protocol stack forencrypting/decrypting the data having other formats instead of theexisting MH format can be defined and thus the conditional accessfunction of the data can be performed. The encrypted service data andcontrol data can be signaled in the physical layer and can betransmitted via the MH transport layer. The control word and theadditional control data necessary for the conditional access can besignaled and stored or can be extracted and used from a storage space inreal time. The service which does not require the conditional access isbypassed and is transmitted via the MH transport layer without having aninfluence on the existing system.

As a result, according to the present invention, when the broadcast isserviced via the MH system, the conditional access can be applied.Accordingly, it is possible to allow the broadcast to be viewed by anauthorized user using the receiver.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A method of processing data in a broadcasttransmitter, the method comprising: encoding broadcast service dataincluded in data units; inserting known data into the encoded broadcastservice data, wherein the known data is to be used for channelestimation in a broadcast receiver; and transmitting a broadcast signalincluding the encoded broadcast service data into which the known datawere inserted, wherein each of the data units includes an M-byte header,k bytes of stuffing data and an (N-M-k)-byte payload, wherein the headerincludes stuffing indication information indicating whether the stuffingdata are included in the corresponding data unit, wherein the payloadincludes the broadcast service data, wherein N and M are integers, andwherein k is equal to or greater than 0.